10.14639/0392-100X-N2262
Objective. Laryngeal chondritis (LC) is a rare complication of carbon dioxide transoral laser microsurgery (CO2 TOLMS) for laryngeal tumours and can pose a diagnostic challenge. Its magnetic resonance (MR) features have not been previously described. This study aims to characterise a cohort of patients who developed LC after CO2 TOLMS and describe its clinical and MR findings. Methods. Clinical records and MR images of all patients presenting with LC after CO2 TOLMS between 2008 and 2022 were reviewed. Results. Seven patients were analysed. Timing of LC diagnosis ranged from 1 to 8 months after CO2 TOLMS. Four patients were symptomatic. Abnormal endoscopic findings included suspected tumour recurrence in 4 patients. MR documented focal or extensive signal changes involving the thyroid lamina and para-laryngeal space with T2 hyperintensity, T1 hypointensity and intense contrast enhancement (n = 7), and minimally reduced mean apparent diffusion coefficient (ADC) values (1.0-1.5 x 10-3 mm2/s) (n = 6). A favourable clinical outcome was achieved in all patients. Conclusions. LC after CO2 TOLMS has a distinctive MR pattern. When tumour recurrence cannot be confidently excluded based on imaging, antibiotic therapy, close clinical and radiological follow-up and/or biopsy are recommended.
text/xml
1827-675X
2262
en
Davide Farina
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
magnetic resonance
Magnetic resonance diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer
Text.Serial.Journal
https://www.actaitalica.it/
43
Laryngology
2023-02-27
2022-08-07
2023-02-28
2023-02-28
32-41
1
Davide Farina
2023/02/27
10.14639/0392-100X-N2262
32
Department of Radiology, University of Brescia, Brescia, Italy; 4 Radiology Unit, Surgery Department, Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Italy
1827-675X
magnetic resonance
en
41
Magnetic resonance diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer
https://www.actaitalica.it/article/download/2262/916
43
ACTA OTORHINOLARYNGOLOGICA ITALICA 2023;43:32-41; doi: 10.14639/0392-100X-N2262




Laryngology


Magnetic resonance diagnosis of laryngeal chondritis
after transoral laser microsurgery for laryngeal cancer
Risonanza magnetica nella diagnosi di condrite laringea post microchirurgia transorale
laser per carcinoma della laringe
Bruno Cunha1, Davide Lancini2, Paolo Rondi3, Marco Ravanelli3, Roberto Maroldi3, Alberto Paderno2, Gabriele Zigliani2,
Ilaria Bertotto4, Cesare Piazza2, Davide Farina3
1
 Neuroradiology Department, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal; 2 Department of
Otorhinolaryngology, Head and Neck Surgery, University of Brescia, Brescia, Italy; 3 Department of Radiology, University of Brescia,
Brescia, Italy; 4 Radiology Unit, Surgery Department, Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Italy


SUMMARY
Objective. Laryngeal chondritis (LC) is a rare complication of carbon dioxide transoral la-
ser microsurgery (CO2 TOLMS) for laryngeal tumours and can pose a diagnostic challenge.
Its magnetic resonance (MR) features have not been previously described. This study aims
to characterise a cohort of patients who developed LC after CO2 TOLMS and describe its
clinical and MR findings.
Methods. Clinical records and MR images of all patients presenting with LC after CO2
TOLMS between 2008 and 2022 were reviewed.
Results. Seven patients were analysed. Timing of LC diagnosis ranged from 1 to 8 months
after CO2 TOLMS. Four patients were symptomatic. Abnormal endoscopic findings in-
cluded suspected tumour recurrence in 4 patients. MR documented focal or extensive signal
changes involving the thyroid lamina and para-laryngeal space with T2 hyperintensity, T1
hypointensity and intense contrast enhancement (n = 7), and minimally reduced mean ap-
parent diffusion coefficient (ADC) values (1.0-1.5 x 10-3 mm2/s) (n = 6). A favourable clini-
cal outcome was achieved in all patients.
Conclusions. LC after CO2 TOLMS has a distinctive MR pattern. When tumour recurrence              Received: August 7, 2022
                                                                                                  Accepted: November 6, 2022
cannot be confidently excluded based on imaging, antibiotic therapy, close clinical and
radiological follow-up and/or biopsy are recommended.
                                                                                                  Correspondence
KEY WORDS: carbon dioxide transoral laser microsurgery, laryngeal tumours, laryngeal              Bruno Cunha
chondritis, head and neck imaging, magnetic resonance                                             Neuroradiology Department, Hospital São José,
                                                                                                  Centro Hospitalar Universitário de Lisboa Central,
                                                                                                  R. José António Serrano, 1150-199 Lisboa, Portugal
RIASSUNTO                                                                                         Tel. +35 1218841000. Fax +35 1218841023
Obiettivo. La condrite laringea (CL) è una rara complicanza della microchirurgia laringea         E-mail: brunojorgecunha@gmail.com
transorale laser (CO2 TOLMS) per neoplasie laringee e può rappresentare una difficile
diagnosi. Le caratteristiche in risonanza magnetica (RM) della CL non sono state descritte.         How to cite this article: Cunha B, Lancini D,
Questo studio vuole caratterizzare una coorte di pazienti che hanno sviluppato CL dopo              Rondi P, et al. Magnetic resonance diagnosis
CO2 TOLMS e descriverne i rilievi clinici e RM.                                                     of laryngeal chondritis after transoral laser mi-
Metodi. Le cartelle cliniche e le RM dei pazienti che hanno presentato CL dopo CO2                  crosurgery for laryngeal cancer. Acta Otorhi-
TOLMS dal 2008 al 2022 sono stati rivisti.                                                          nolaryngol Ital 2023;43:32-41. https://doi.
Risultati. Sette pazienti sono stati analizzati. Il tempo di comparsa della CL variava da 1 a       org/10.14639/0392-100X-N2262
8 mesi dopo CO2 TOLMS. Quattro pazienti erano sintomatici. Rilievi endoscopici anomali
hanno incluso la sospetta recidiva in 4 pazienti. La RM ha mostrato alterazioni di segnale        © Società Italiana di Otorinolaringoiatria
                                                                                                  e Chirurgia Cervico-Facciale
focali o diffuse delle lamine tiroidee e dello spazio paralaringeo con iperintensità T2, ipoin-
tensità T1, intenso enhancement in 7 pazienti e ADC medio minimamente ridotto (1,0-1,5 x
                                                                                                                 OPEN ACCESS
10-3 mm2/s) in 6 pazienti. Tutti i casi hanno avuto un decorso clinico favorevole.
Conclusioni. La CL dopo CO2 TOLMS ha una pattern RM distintivo. Quando la recidiva                This is an open access article distributed in accordance with
                                                                                                  the CC-BY-NC-ND (Creative Commons Attribution-Non-
neoplastica non può essere esclusa sulla base dell’imaging, si raccomandano terapia anti-         Commercial-NoDerivatives 4.0 International) license. The
biotica, stretto follow-up clinico e radiologico e/o biopsia.                                     article can be used by giving appropriate credit and mentio-
                                                                                                  ning the license, but only for non-commercial purposes and
PAROLE CHIAVE: microchirurgia laringea transorale laser, neoplasie laringee, condrite             only in the original version. For further information: https://
laringea, imaging del testa-collo, risonanza magnetica                                            creativecommons.org/licenses/by-nc-nd/4.0/deed.en




32
                                                       MR diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer




Introduction                                                         MR acquisition and image analysis
                                                                     The following sequences were acquired in all patients: T2-
Carbon dioxide transoral laser microsurgery (CO2                     weighted and T1-weighted sequences, diffusion-weighted
TOLMS) 1 is an effective therapeutic option for the surgical         imaging (DWI) and a volumetric T1-weighted gradient-
treatment of selected laryngeal tumours, with high chances           echo sequence with fat saturation after contrast injection
of local control, minimal functional impairment and low              (VIBE). Motion-compensated sequences and dedicated
rates of procedure-related complications 2-6. In detail, if the      surface coils were utilised 20. MR images were reviewed in
laryngeal tumour is clearly visualised and fully exposed             consensus by a fifth-year resident in Neuroradiology and an
under direct laryngoscopy 7,8, CO2 TOLMS is suitable                 experienced head and neck radiologist.
for laryngeal cancers ranging from T1 to selected T3 (T3
tumours due to invasion of the anterior paraglottic space
or T3 tumours in patients unfit for open partial horizon-            Results
tal laryngectomy) 9,10. The most frequently described late
complications of such a surgical approach include aspira-            Patient cohort and clinical findings
tion pneumonia, vocal fold scarring, anterior commissure             A total of 7 patients (5 males, 2 females) were included in
synechia and laryngeal granuloma 11-14. Laryngeal chondri-           the present case series. Table I summarises the baseline and
tis (LC) is very rarely reported, with a maximum rate of             follow-up clinical characteristics of patients. Median age
1% 12,15-17. In our referral tertiary academic centre, a series      was 65 years (range, 58-78). Five patients were affected
of cases of LC following CO2 TOLMS for laryngeal tu-                 by glottic tumours and were submitted to CO2 TOLMS
mours were identified on follow-up by magnetic resonance             cordectomy, while 2 were affected by supraglottic tumours
(MR). Radiological and clinical differentiation from tu-             and underwent CO2 TOLMS supraglottic resections. Two
mour recurrence proved to be challenging in most of these            patients were re-submitted to CO2 TOLMS: patient No. 2
cases. Existing literature on this subject is scarce and, to         four months after the first procedure, due to tumour persis-
our knowledge, the MR features of this complication have             tence, and patient No. 4 one month after the first resection,
not been previously addressed. Therefore, this study aims            due to positive margins on histopathological examination.
to characterise a cohort of patients who developed LC fol-           Regarding patients’ history and comorbidities, one patient
lowing CO2 TOLMS for laryngeal cancer, in order to raise             (No. 6) reported previous bilateral cordectomies (type I
awareness on this possible complication, and describe its            and type II) 13 years earlier for glottic tumours and was
clinical findings and key MR features.                               diagnosed with type 2 diabetes. Moreover, another patient
                                                                     (No. 4) had a previous diagnosis of thyroid carcinoma and
Materials and methods                                                underwent total thyroidectomy and cobalt therapy 40 years
                                                                     before. No other patients were submitted to any form of
A retrospective search of clinical records and MR data of            radiotherapy.
all patients presenting with LC as a complication of CO2             Timing of LC diagnosis ranged from 1 to 8 months (mean,
TOLMS between 2008 and 2022, as registered in the head               4) after CO2 TOLMS. At diagnosis, 4 patients were symp-
and neck database of University of Brescia, was carried out.         tomatic: patient No. 2 presented with dysphonia and effort-
                                                                     related dyspnoea, patient No. 5 with rapidly progressive
Clinical data                                                        dyspnoea, patient No. 6 with odynophagia and liquid dys-
Baseline demographic and clinical data, surgical procedure           phagia and patient No. 7 with dysphonia alone. The re-
description and clinical outcomes were retrieved from pa-            maining 3 patients were asymptomatic.
tients’ records.                                                     Abnormal endoscopic findings were present in 6 patients:
                                                                     4 patients presented endoscopic findings suspicious for
Surgical procedure                                                   tumour recurrence, while 2 presented glottic granulomas
All patients were submitted to glottic or supraglottic CO2           (one with a coexistent anterior commissure synechia).
TOLMS. Types of resection were classified according to
the European Laryngological Society (ELS) classifications            Imaging findings
for glottic 18 and supraglottic endoscopic resections 19. Im-        MR scans with findings of LC after CO2 TOLMS were
aging follow-up at our center is performed with MR every 6           performed in the context of: further investigation of abnor-
months during the first 2 years and annually thereafter. All         mal laryngoscopic findings in one asymptomatic patient
patients were homogeneously followed by the same group               (No. 1), further investigation in 4 symptomatic patients
of head and neck radiologists.                                       (No. 2, No. 5, No. 6 and No. 7), and routine follow-up in 2



                                                                                                                                               33
B. Cunha et al.




Table I. Patients baseline and follow-up clinical characteristics and management.
 Patient Gender         Age         Tumour site,       Type of CO2         Timing                 Clinical       Endoscopic findings                Management
 (No.)                (years) histotype, and              TOLMS             of LC                findings
                                      staging                             diagnosis
 1            Male         65          Supraglottic      Type I supraglottic    4 months      Asymptomatic       Ipsilateral false vocal           Antibiotic therapy
                                      NEC T2N0M0           laryngectomy                                              cord vegetative           US-guided and transoral
                                                                                                                 tissue and vocal cord          biopsies: inflammatory
                                                                                                                      hypomobility              granulation tissue; no
                                                                                                                                                  evidence of tumour
                                                                                                                                              Regular FU: MR at 1, 3, 6
                                                                                                                                              and 9 (resolution) months
 2           Female        75          Glottic SCC      Type II cordectomy      2 months        Dysphonia        Anterior commissure               Antibiotic therapy
                                        T1N0M0            (followed by a                        and effort-     lesion with NBI pattern            US-guided biopsy:
                                                         second Type Va                           related        suspicious for tumour        inflammatory granulation
                                                          cordectomy 4                          dyspnoea              persistence               tissue; no evidence of
                                                          months later)                                                                                 tumour
                                                                                                                                              Regular FU: MR at 2 and
                                                                                                                                                6 (resolution) months;
                                                                                                                                             laryngoscopy at 5 months
 3            Male         58          Glottic SCC           Type Vcd           3 months      Asymptomatic Ipsilateral anterior-third           Open partial horizontal
                                        T2N0M0              cordectomy                                       vocal cord, anterior           (supracricoid) laryngectomy:
                                                                                                               commissure and                   no evidence of tumour
                                                                                                           contralateral vocal cord
                                                                                                           lesions with NBI pattern
                                                                                                            suspicious for tumour
                                                                                                                  persistence
 4            Male         72          Supraglottic           Type IIIb         8 months      Asymptomatic Expected post-surgical                   US-guided biopsy:
                                      SCC T3N0M0           supraglottic                                             findings                  inflammatory granulation
                                                          laryngectomy                                                                           tissue; no evidence of
                                                             (followed                                                                                   tumour
                                                            by margin                                                                               Antibiotic therapy
                                                         enlargement one
                                                           month later)                                                                      Regular FU: MR at 6, 8 and
                                                                                                                                                11 (resolution) months;
                                                                                                                                               laryngoscopy at 6 and 8
                                                                                                                                                         months
 5           Female        64          Glottic SCC            Type Vd            1 month         Rapidly             Irregular tissue               Antibiotic therapy
                                        T1N0M0              cordectomy                         progressive      thickening on ipsilateral          Transoral biopsies:
                                                                                                dyspnoea           vocal cord, anterior       inflammatory granulation
                                                                                                                    commissure and               tissue; no evidence of
                                                                                                                        subglottis                       tumour
                                                                                                                                             Resolution at 6 months FU
                                                                                                                                                            MR
 6            Male         78       Recurrent glottic     Type Vabcd            7 months       Odynophagia       Anterior commissure                Antibiotic therapy
                                     SCC T1aN0M0          cordectomy                            and liquid        synechia and small                FU: MR at 2 and 6
                                     (T1bN0M0 13          (followed by                          dysphagia         ipsilateral posterior            (resolution) months
                                      years before)   contralateral Type                                         vocal cord granuloma
                                                        II cordectomy)
 7            Male         58          Glottic SCC           Type Va            6 months        Dysphonia        Ipsilateral vocal cord     Antibiotic and corticosteroid
                                        T1N0M0            cordectomy                                                   granuloma                       therapy
                                                                                                                                             Videolaryngoscopy-guided
                                                                                                                                                biopsy: inflammatory
                                                                                                                                               granulation tissue; no
                                                                                                                                                 evidence of tumour
                                                                                                                                            Resolution at 2 months FU MR
CO2 TOLMS: Carbon dioxide transoral laser microsurgery; FU: Follow-up; LC: Laryngeal chondritis; MR: Magnetic resonance; NBI: Narrow-band imaging; NEC: Neuroendocrine carci-
noma; No.: number; SCC: Squamous cell carcinoma; US: Ultrasound.




34
                                                                      MR diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer




asymptomatic patients (No. 3 and No. 4). The key MR find-                            Table II. MR findings.
ings encountered in these scans are summarised in Table II.                           Feature                                                                  (n)
All patients displayed signal changes involving the para-                             High signal on T2-WI                                                     7/7
glottic space and thyroid lamina. High signal intensity on                            Low signal on T1-WI                                                      7/7
T2-weighted images (WI), low signal intensity on T1-WI                                Minimally reduced mean ADC values                                        6/7
and contrast-enhancement were present in all patients. T1-                            (1.04-1.45 x 10-3 mm2/s)
WI signal was hypointense compared to ossified cartilage,                             Contrast enhancement                                                     7/7
but it was slightly hyperintense compared to non-ossified                             Homogeneous                                                              1/7
cartilage (Fig. 1). The contrast-enhancement pattern was                              Intense peripheral enhancement                                           6/7
homogeneously intense in one patient, while 6 showed                                  Central avascular components                                             1/7
intense peripheral enhancement with less intense central                              Focal full thickness thyroid cartilage erosion/involvement               5/7
enhancement (5 patients) (Figs. 1, 2) or central avascular                            Paraglottic space involvement                                            5/5
components (1 patient) (Fig. 3). DWI documented mini-
                                                                                      Lesion extension along external surface of thyroid lamina                5/5
mally reduced mean apparent diffusion coefficient (ADC)
                                                                                      Extensive full thickness thyroid cartilage erosion/involvement           2/7
values in 6 patients (mean ADC values ranging from 1.035
                                                                                      Involvement of the cricoarytenoid unit                                   1/7
to 1.45 x 10-3 mm2/s). Two main distribution patterns were
                                                                                     ADC: Apparent Diffusion Coefficient; MR: Magnetic resonance; WI: Weighted images.
distinguished: (1) focal thyroid chondritis/perichondritis
(registered in 5 patients) and (2) extensive thyroid chondri-
tis/perichondritis (registered in 2 patients). In the focal pat-                     thyroid lamina and deep laryngeal involvement adjacent to
tern group, full thickness focal cartilage erosion/involve-                          the inner surface of the thyroid cartilage were present in all
ment, lesion extension along the external surface of the                             5 cases. In the extensive pattern group, major signal chang-


  A                                                      B                                                       C




  D                                                      E                                                       F




Figure 1. Focal post-CO2 TOLMS LC in patient No. 6. Axial images at the supraglottic level: TSE T2-weighted (A), T1-weighted (B), contrast-enhanced fat-satu-
rated T1 (VIBE) (C), DWI b900 (D) and ADC map (E). Focal lesion (arrows) involving the anterior residual left false vocal cord and the full thickness of the adjacent
segment of the thyroid lamina. It is characterised by T2-weighted hyperintensity and T1-weighted hypointensity compared to ossified cartilage (dotted arrow in
B), while it shows T1-weighted slightly hyperintense signal compared with non-ossified cartilage (arrowheads in B). There is intense peripheral contrast enhance-
ment (arrows in C) and minimal diffusion restriction pattern (hyperintense signal on DWI and corresponding hypointense signal at the ADC map; mean ADC value
of 1.2 x 10-3 mm2/s). Axial contrast-enhanced fat-saturated T1 (VIBE) at 2 months follow-up (F) shows marked improvement of the LC process, with size reduction
and decreased contrast enhancement of the focal lesion (arrow in F).



                                                                                                                                                                     35
B. Cunha et al.




  A                                                     B                                                     C




  D                                                     E                                                     F




Figure 2. Focal post-CO2 TOLMS LC in patient No. 3. Axial images at the glottic level (A, D and F) and immediately superior supraglottic level (B, C and E): T2-
weighted (A and B), T1-weighted (C), contrast-enhanced fat-saturated T1 (VIBE) (D and E) and DWI b900 (F). Focal para-commissural lesion (arrows in A and D)
at the residual left vocal cord, anterior to the T2 hypointense signal region of the cordectomy scar (asterisks in A and B). It extends deeply and involves the full
thickness of the adjacent anterior thyroid lamina (dotted arrows in B, C and E). Notice slight extension along the external surface of the thyroid lamina anteriorly
(arrowheads in B, C and E). This lesion shows slightly elevated T2-weighted signal, low T1-weighted signal, intense peripheral contrast enhancement and minimal
diffusion restriction pattern (mean ADC value of 1.1 x 10-3 mm2/s; ADC map not shown). While this lesion could be misdiagnosed as tumour recurrence, a biopsy
confirmed post-CO2 TOLMS thyroid chondritis.


es and swelling of the thyroid laminas were present. Patient                        py-guided and/or transoral biopsies were performed in 5
No. 2 showed involvement of the superior two thirds of the                          patients, showing inflammatory granulation tissue and no
laminae (Fig. 3), while in patient No. 5 both the entire lami-                      evidence of tumour. One patient was submitted to open par-
nae as well as the left cricoarytenoid unit were involved.                          tial horizontal (supracricoid) laryngectomy and no signs of
                                                                                    tumour recurrence were present at histopathological exam.
Management and follow-up                                                            Chondritis resolution was documented by follow-up MR in
In the focal LC pattern group, MR findings were interpreted                         6 patients (Figs. 4, 5). Time to resolution ranged from 2 to
as a possible/probable inflammatory process in 2 patients                           11 months.
and as probable tumour recurrence in another 2. In one pa-
tient, MR findings were initially interpreted as probable tu-
                                                                                    Discussion
mour recurrence, but were later re-considered as a possible
inflammatory process. In 2 cases with an extensive LC pat-                          The present paper describes a series of patients who de-
tern, MR findings were promptly recognised as chondritis.                           veloped inflammatory/infectious laryngeal complica-
Clinical management and follow-up strategy are described                            tions – namely thyroid chondritis and perichondritis (an
in Table I. Antibiotic therapy was performed in 6 patients.                         inflammatory process which may result in infection or
Ultrasound (US)-guided transcutaneous, videolaryngosco-                             necrosis) – after CO2 TOLMS. Because such a complica-



36
                                                                     MR diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer




 A                                                      B                                                     C




 D                                                      E                                                     F




Figure 3. Extensive post-CO2 TOLMS thyroid chondritis in patient No. 2. Different axial sequences at the level of the false vocal cords: T2-weighted (A), DWI
b900 (B), ADC map (C), T1-weighted (D) and contrast-enhanced fat-saturated T1 (VIBE) (E), and soft-tissues window axial CT reconstruction at the glottic level (F).
Swollen appearance and extensive full thickness signal changes of both thyroid laminae with very hyperintense T2-weighted and isointense T1-weighted signal,
peripheral areas with diffusion restriction pattern, as demonstrated by high signal on DWI b900 and corresponding low signal on ADC map (arrowheads in B and
C; mean ADC values of 1.05 x 10-3 mm2/s), and intense peripheral contrast enhancement with central avascular areas (asterisks in E). Consequent reduction of
the airway. On CT, there is extensive erosion of both thyroid laminae and only its most posterior segments are visible (arrows in F).


tion has not been previously addressed in the radiological                          viewed in the literature. Despite the low rates reported,
literature, this setting poses a non-negligible clinical chal-                      prophylactic measures are regularly applied and standard
lenge. In detail, tumour recurrence was suspected in 2 MR                           protocol at our institution includes prophylactic antibiotic
exams and could not be confidently excluded in 3 cases.                             therapy with ampicillin whenever thyroid cartilage has
Therefore, the purpose of our work was to investigate these                         been extensively exposed or partially resected. Vilaseca-
clinical pictures in order to acquire a better understanding                        González and colleagues found that large tumour exten-
of this complication and to identify its key imaging fea-                           sion (cT3) and presence of diabetes was associated with
tures, as well as trying to differentiate it from possible local                    higher complication rates, while no association was found
tumour recurrence.                                                                  with tumour site or patient’s age 16. In our series, only one
As reported in the literature, CO2 TOLMS carries a rel-                             patient had a relevant medical history of diabetes. Abou-
atively low risk of procedure-related complications 16.                             yared et al. reported an incidence of chondronecrosis of
These can be classified as intraoperative or post-operative                         23% after CO2 TOLMS in a cohort of 52 patients previ-
(early or delayed) 12. Post-surgical bleeding represents the                        ously submitted to radiotherapy 24. However, the majority
most frequent intra- and/or early post-operative compli-                            of these patients were submitted to CO2 TOLMS within
cation 5,16,21,22. By contrast, the most commonly reported                          5 years after radiotherapy. In our series, a single patient
late complications include aspiration pneumonia (1.4%-                              was previously submitted to radiotherapy 40 years before
11.5%) 11,12,16,21,22, vocal fold scarring with anterior glot-                      surgery. Regarding the type of resection, it is important
tic synechia (4.5%-10.6%) 2,13,14 and laryngeal granuloma                           to stress that all patients in our series submitted to glottic
(2%-10.6%) 13,14,23. Although a potential risk for local in-                        procedures underwent a type V cordectomy. It is conceiv-
fection is always present in any surgical intervention on                           able that extensive cordectomies like these are associated
the larynx, LC after CO2 TOLMS is rarely described, with                            with higher risk of inflammatory/infectious complica-
only a few series reporting rates ranging from 0.3% to                              tions, particularly due to cartilage exposure and internal
1% 12,15-17.                                                                        perichondrium removal. It is also plausible that patients
Inflammatory/infectious complications following CO2                                 re-submitted to CO2 TOLMS, generally with broader re-
TOLMS and its risk factors have not been extensively re-                            sections, could face a higher risk of complication. In fact,



                                                                                                                                                               37
B. Cunha et al.




  A                                                                                B




  C                                                                                D




Figure 4. Focal post-CO2 TOLMS LC in patient No. 4. Axial images at the glottic level: fat-saturated T2-weighted (A), contrast-enhanced fat-saturated T1 (VIBE)
(B) and soft-tissues window CT reconstruction (C). Focal signal changes involving the full thickness of the left anterior thyroid lamina (arrows) with very hyperin-
tense T2-weighted signal and intense peripheral contrast enhancement. Note the extension along the external perichondrial surface of the thyroid lamina anteriorly
(arrowhead). On CT, focal full thickness erosion of the corresponding segment of the thyroid lamina is depicted (double-headed dashed arrow on C). Axial con-
trast-enhanced fat-saturated T1 (VIBE) (D) at 11 months follow-up shows complete resolution of the LC process, with no abnormal contrast enhancement areas.


3 patients in our series were re-submitted to laser surgery.                        volume loss and scar tissue within the surgical area, which
Symptoms and clinical findings were unspecific or non-                              is characteristically very hypointense on T2-WI with vari-
existent. Four symptomatic patients presented with rapidly                          able heterogenous contrast enhancement 20. On the other
progressive dyspnoea, effort-related dyspnoea, dysphonia,                           hand, in the setting of post-CO2 TOLMS LC we found a
odynophagia and liquid dysphagia. Three patients were                               distinctive MR pattern characterised by soft tissue and thy-
asymptomatic and, in these cases, LC was diagnosed dur-                             roid lamina signal changes with high signal on T2-WI, low
ing regular clinical (laryngoscopy) or radiological (MR)                            signal on T1-WI, minimally reduced mean ADC values
follow-up. Abnormal endoscopic findings were frequent                               and intense contrast-enhancement, most frequently intense
but not suggestive of an infectious complication. Endo-                             peripheral enhancement. Focal and extensive chondritis/
scopic findings suspicious for tumour recurrence were                               perichondritis patterns were registered. Cases with focal
present in 4 cases (including 2 symptomatic patients). La-                          pattern consistently showed focal full thickness cartilage
ryngeal granulomas were found in 2 symptomatic patients                             involvement and extension of the infectious process along
(one patient also showing an anterior commissure syn-                               the external margins of the thyroid laminae. This pattern
echia). In one asymptomatic case, no unexpected findings                            proved to be the most challenging to diagnose, illustrating
were registered.                                                                    the importance of awareness on the possibility of post-CO2
We have previously described the expected imaging chang-                            TOLMS LC and its key imaging features. Compared to LC,
es following CO2 TOLMS, consisting of visualisation of                              tumour persistence/local recurrence most often appears as



38
                                                                     MR diagnosis of laryngeal chondritis after transoral laser microsurgery for laryngeal cancer




  A                                                      B                                                      C




  D                                                      E                                                      F




Figure 5. Chondritis evolution in patient No. 1. Axial T2-weighted (A, B, C) and contrast-enhanced fat-saturated T1 (VIBE) (D, E, F) images. Post-CO2 TOLMS
larynx MR (A, D) shows a lesion centred in the right paraglottic space deep to the middle and anterior thirds of the false vocal cord (asterisk) with bulging of the
mucosa and consequent reduction of the airway. The lesion shows focal extension through the full thickness of the thyroid lamina (arrow) and along its external
perichondral surface (arrowhead). It is characterized by T2-weigthed hyperintense signal and intense homogenous contrast enhancement. At one month follow-up
(B, E), there was reduction of the extension of the lesion and decreased contrast enhancement. At 6 months follow-up (C, F), there was near-complete resolution
of the LC process. An area of T2 low signal (scar tissue) with subtle contrast enhancement is now visible in the paraglottic space (asterisk) and the thyroid lamina
appears as newly ossified (arrow).


a focal submucosal lesion with a lower (intermediate) T2-                           and feasible in these patients. Resolution of MR changes
WI signal, diffusion restriction pattern on DWI and a dif-                          was consistently registered, except in the patient submitted
fuse, though less intense, contrast enhancement pattern 20.                         to open partial resection in which the extent of laryngeal
On the other hand, cases with an extensive pattern showed                           framework compromise made it necessary to remove both
near-total involvement of the thyroid laminae, which ap-                            thyroid laminae extensively involved by the LC process to
peared diffusively swollen, and were promptly recognised                            avoid further airway complications. A favourable clinical
as probable chondritis. The morphologic and signal chang-                           outcome was achieved in all patients.
es mirror those witnessed in chondroradionecrosis, which                            Limitations of the present study include its retrospective
are widely described in the literature and are therefore eas-                       design and the paucity of the case series, which did not al-
ier to interpret.                                                                   low for appropriate statistical analysis.
Despite the recognition of this distinctive MR pattern, our
opinion is that confident exclusion of tumour recurrence,
                                                                                    Conclusions
in most cases, is not possible based on imaging alone. In
our series, all patients were submitted to close clinical and/                      LC is a rare but challenging complication of CO2 TOLMS
or MR follow-up. Antibiotic therapy was administered                                that laryngologists and radiologists should be aware of.
in most patients (6 cases). Tumour recurrence was histo-                            Despite having unspecific clinical findings, it shows a
pathologically excluded in 6 patients (following biopsy in                          distinctive MR pattern characterised by signal changes in
5 cases and open partial horizontal laryngectomy in one).                           cartilage and adjacent soft tissues with T2-WI hyperinten-
US-guided transcutaneous biopsy is a widely accessible                              sity, T1-WI hypointensity, minimally reduced mean ADC
option and, according to our experience, seems to be safe                           values and peripheral contrast enhancement. Focal or ex-



                                                                                                                                                                39
B. Cunha et al.




tensive patterns of LC can be documented. Dissemination                          595 patients. Head Neck 2010;32:977-983. https://doi.org/10.1002/
of the inflammatory/infectious process along the external                        hed.21278
surface of the thyroid cartilage seems to be characteristic in
                                                                            5
                                                                                 Peretti G, Piazza C, Ansarin M. Transoral CO2 laser microsur-
                                                                                 gery for Tis-T3 supraglottic squamous cell carcinomas. Eur Arch
the focal pattern; the extensive pattern resembles chondro-                      Otorhinolaryngol 2010;267:1735-1742. https://doi.org/10.1007/
radionecrosis. When tumour recurrence cannot be confi-                           s00405-010-1284-1
dently excluded based on imaging alone, antibiotic therapy,                 6
                                                                                 Piazza C, Paderno A, Del Bon F, et al. Long-term oncologic outcomes
close clinical and radiological follow-up and/or biopsy are                      of 1188 Tis-T2 glottic cancers treated by transoral laser microsur-
                                                                                 gery. Otolaryngol Head Neck Surg 2021;165:321-328. https://doi.
recommended.
                                                                                 org/10.1177/0194599820983727
                                                                            7
                                                                                 Piazza C, Paderno A, Grazioli P, et al. Laryngeal exposure and margin
Conflict of interest statement                                                   status in glottic cancer treated by transoral laser microsurgery. La-
The authors declare no conflict of interest.                                     ryngoscope 2018;128:1146-1151. https://doi.org/10.1002/lary.26861
                                                                            8
                                                                                 Piazza C, Mangili S, Bon FD, et al. Preoperative clinical predictors
Funding                                                                          of difficult laryngeal exposure for microlaryngoscopy: the Laryngo-
                                                                                 score. Laryngoscope 2014;124:2561-2567. https://doi.org/10.1002/
This research did not receive any specific grant from fund-
                                                                                 lary.24803
ing agencies in the public, commercial, or not-for-profit                   9
                                                                                 Peretti G, Piazza C, Penco S, et al. Transoral laser microsurgery as
sectors.                                                                         primary treatment for selected T3 glottic and supraglottic cancers.
                                                                                 Head Neck 2016;38:1107-1112. https://doi.org/10.1002/hed.24424
Author contributions                                                        10
                                                                                 Amin MB, Edge SB, Greene FL, et al., editors. American Joint Com-
BC: reviewed the subject, performed the literature search                        mittee on Cancer. AJCC cancer staging manual. Eighth Edition. New
                                                                                 York: Springer; 2017.
and clinical data analysis, collected, analyzed and reviewed
                                                                            11
                                                                                 Roh J-L, Kim D-H, Park C Il. Voice, swallowing and quality of life in
the images, wrote and reviewed the manuscript; DL, AP,
                                                                                 patients after transoral laser surgery for supraglottic carcinoma. J Surg
GZ, CP: collected and analyzed the clinical data and re-                         Oncol 2008;98:184-189. https://doi.org/10.1002/jso.21101
viewed the manuscript; PR: helped writing and reviewed                      12
                                                                                 Miguel C, Estomba C, Alberto F, et al. Complications in CO2 laser
the manuscript; MR: conceptualized the manuscript, col-                          transoral microsurgery for larynx carcinomas. Int Arch Otorhinolaryn-
lected, analyzed and reviewed the images, helped writing                         gol 2016;20:151-155. https://doi.org/10.1055/s-0035-1569145
and reviewed the manuscript; RM: conceptualized the                         13
                                                                                 Lee M, Buchanan MA, Orl-hns F, et al. Complications after CO2
                                                                                 laser surgery for early glottic cancer: an institutional experience.
manuscript and reviewed the images and the manuscript;
                                                                                 Head Neck 2016;38 (Suppl 1):e987-e990. https://doi.org/10.1002/
IL: collected and reviewed the images; DF: reviewed the                          hed.24142
images and the manuscript.                                                  14
                                                                                 Galli A, Giordano L, Sarandria D, et al. Oncological and complica-
                                                                                 tion assessment of CO2 laser-assisted endoscopic surgery for T1-
Ethical consideration                                                            T2 glottic tumours: clinical experience. Acta Otorhinolaryngol Ital
                                                                                 2016;36:167-173. https://doi.org/10.14639/0392-100X-643
This study was approved by the Clinical Research Ethi-
                                                                            15
                                                                                 Hinni ML, Salassa JR, Grant DG, et al. Transoral laser microsurgery
cal Committee of University of Brescia (protocol number                          for advanced laryngeal cancer. Arch Otolaryngol Head Neck Surg
NP4267). The research was conducted ethically, with all                          2007;133:1198-1204. https://doi.org/10.1001/archotol.133.12.1198
study procedures being performed in accordance with the                     16
                                                                                 Vilaseca-González I, Bernal-Sprekelsen M, Blanch-Alejandro J-L, et
requirements of the World Medical Association’s Declara-                         al. Complications in transoral CO2 laser surgery for carcinoma of the
tion of Helsinki. Informed consent was waived.                                   larynx and hypopharynx. Head Neck 2003;25:382-388. https://doi.
                                                                                 org/10.1002/hed.10207
                                                                            17
                                                                                 Ellies M, Steiner W. Peri- and post-operative complications after laser
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