10.5826/dpc.1202a85
Introduction: Eccrine porocarcinoma (EPC) is a rare subtype of non-melanoma skin cancer developing in the intraepithelial portion of eccrine sweat glands. It is branded with a highly metastatic potential and increased rate of local recurrence after treatment. EPC showcased a trend of developing on the extremities, with presentation on the face sparse.
Objectives: Aim of the study was to evaluate the frequency, clinical features, and course of this malignancy presented on the face.
Methods: A retrospective review of the skin cancers excised between January 2010 and June 2021 was conducted in the plastic surgery department of a tertiary hospital. Patients were included in the study if EPC on the face was histologically confirmed. A prospectively maintained clinic database and the pathological reports were used to collect data.
Results: 4 EPC cases on the face out of 3984 confirmed skin cancers were identified. None of the cases was suspected clinically, but the diagnosis was established following the histopathologic examination. An aggressive postoperative behavior was confirmed in two cases.
Conclusions: The variance in the clinical presentation and the non-specific characteristics are perplexing clinical diagnosis, with the histopathologic examination representing the current standard for confirmation. Early diagnosis and adequate surgical resection are recommended as treatment cornerstones. Clinical awareness ought to be raised and a definitive treatment protocol be established for optimized results.
text/xml
2160-9381
1966
en
Efstathios Lykoudis
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
sweat gland
Eccrine Porocarcinoma of the face is a great imitator with aggressive behavior
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Original Article
2022-05-02
2021-08-17
2022-05-02
2022-05-24
e2022085
Dermatol Pract Concept
Introduction: Eccrine porocarcinoma (EPC) is a rare subtype of non-melanoma skin cancer developing in the intraepithelial portion of eccrine sweat glands. It is branded with a highly metastatic potential and increased rate of local recurrence after treatment. EPC showcased a trend of developing on the extremities, with presentation on the face sparse.
Objectives: Aim of the study was to evaluate the frequency, clinical features, and course of this malignancy presented on the face.
Methods: A retrospective review of the skin cancers excised between January 2010 and June 2021 was conducted in the plastic surgery department of a tertiary hospital. Patients were included in the study if EPC on the face was histologically confirmed. A prospectively maintained clinic database and the pathological reports were used to collect data.
Results: 4 EPC cases on the face out of 3984 confirmed skin cancers were identified. None of the cases was suspected clinically, but the diagnosis was established following the histopathologic examination. An aggressive postoperative behavior was confirmed in two cases.
Conclusions: The variance in the clinical presentation and the non-specific characteristics are perplexing clinical diagnosis, with the histopathologic examination representing the current standard for confirmation. Early diagnosis and adequate surgical resection are recommended as treatment cornerstones. Clinical awareness ought to be raised and a definitive treatment protocol be established for optimized results.
Efstathios Lykoudis
2022/05/02
10.5826/dpc.1202a85
e2022085
Department of Plastic Surgery, Medical School, University of Ioannina, Greece.
2160-9381
sweat gland
en
e2022085
Huet P, Dandurand M, Pignodel C, Guillot B. Metastasizing eccrine porocarcinoma: report of a case and review of the literature. J Am Acad Dermatol. 1996;35(5):860-864. DOI:10.1016/s0190-9622(96)90105-x. PMID: 8912607.
Eccrine Porocarcinoma of the face is a great imitator with aggressive behavior
https://dpcj.org/index.php/dpc/article/download/1966/1555
                     Dermatology Practical & Conceptual


         Eccrine Porocarcinoma of the Face is a Great
              Imitator With Aggressive Behavior
       Konstantinos Seretis1, Nikolaos Bounas1, Evangeli Lampri2, Efstathios G. Lykoudis1


1 Department of Plastic Surgery, Medical School, University of Ioannina, Ioannina, Greece.
2 Pathology Department, Medical School, University of Ioannina, Ioannina, Greece.



Key words: eccrine porocarcinoma, face, skin cancer, sweat gland
Citation: Seretis K, Bounas N, Lampri E, Lykoudis EG. Eccrine Porocarcinoma of the face is a great imitator with aggressive behavior.
Dermatol Pract Concept. 2022;12(2):e2022085. DOI: https://doi.org/10.5826/dpc.1202a85
Accepted: September 14, 2021; Published: April 2022
Copyright: ©2022 Seretis K et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing interests: None.
Authorship: All authors have contributed significantly to this publication
Corresponding author: Konstantinos Seretis, Department of Plastic Surgery, Ioannina University School of Medicine Leoforos St. Niarchou,
45500, Ioannina, Greece. E-mail: drseretis@uoi.gr




  ABSTRACT             Introduction: Eccrine porocarcinoma (EPC) is a rare subtype of non-melanoma skin cancer developing
                       in the intraepithelial portion of eccrine sweat glands. It is branded with a highly metastatic potential
                       and increased rate of local recurrence after treatment. EPC showcased a trend of developing on the
                       extremities, with presentation on the face sparse.
                       Objectives: Aim of the study was to evaluate the frequency, clinical features, and course of this malig-
                       nancy presented on the face.
                       Methods: A retrospective review of the skin cancers excised between January 2010 and June 2021 was
                       conducted in the plastic surgery department of a tertiary hospital. Patients were included in the study
                       if EPC on the face was histologically confirmed. A prospectively maintained clinic database and the
                       pathological reports were used to collect data.
                       Results: 4 EPC cases on the face out of 3984 confirmed skin cancers were identified. None of the cases
                       was suspected clinically, but the diagnosis was established following the histopathologic examination.
                       An aggressive postoperative behavior was confirmed in 2 cases.
                       Conclusions: The variance in the clinical presentation and the non-specific characteristics are per-
                       plexing clinical diagnosis, with the histopathologic examination representing the current standard for
                       confirmation. Early diagnosis and adequate surgical resection are recommended as treatment corner-
                       stones. Clinical awareness ought to be raised and a definitive treatment protocol be established for
                       optimized results.




Original Article | Dermatol Pract Concept. 2022;12(2):e2022085                                                                          1
Introduction
Skin cancer is the most common type of cancer encountered
worldwide. However, skin malignancies originating from
the sweat glands account only for 1% of these lesions [1].
Eccrine porocarcinoma (EPC) is a very rare subtype, repre-
senting only 0.005% of cutaneous tumors [2]. Most often
witnessed in people aged over 60 years, it is characterized
by a highly metastatic potential and increased rate of local
recurrence, even after excision. EPC showcased a trend of
developing on the extremities, with presentation on the face
sparse [2].


Objectives
Aim of the current study was to evaluate the frequency, clin-
ical features, and course of EPC presented on the face, shed-
ding light on this rare malignancy.


Methods
An observational cohort study was conducted in the Plastic
Surgery Department of a tertiary hospital, using a predeter-
mined protocol, which conformed to the ethical guidelines
of the 1975 Declaration of Helsinki, approved by the local
ethical committee and adhered to the STROBE statement for
                                                                  Figure 1. Eccrine Porocarcinoma - Macroscopic appearance of
cohort studies. All patients who underwent excision of a skin
                                                                  patient 4.
cancer in the department between January 2010 and June
2021 were identified. Patients were included in the study if
EPC on the face was histologically confirmed. A prospec-          possibility of apocrine differentiation. Ducts were revealed
tively maintained clinic database and the pathological re-        with Periodic acid–Schiff stain and immunohistochemically
ports were used to collect data. Outcomes of interest were        with CK19, CEA and EMA.
the EPC incidence, the clinical and pathological characteris-        The characteristics and clinical course are depicted in
tics and the postoperative course of the sample.                  Table 1. An aggressive behavior with local recurrence was
                                                                  revealed in 2 cases, despite the excision with clear margins
                                                                  in both cases and the radiotherapy course, which followed
Results
                                                                  (Figure 3).
Four cases of EPC out of 3984 confirmed skin tumors (fre-
quency: 0.1%) were revealed. None of the cases was suspected
                                                                  Conclusions
clinically, but they were resected as non-melanoma skin
tumors with 5-mm surgical margins (Figure 1) [3]. The di-         EPC is considered one of the rarest skin tumors a surgeon
agnosis was established following the histopathologic exam-       can encounter. Although it develops often on the extremities,
ination, based on the presence of irregular dermis-infiltrating   the face in particular the auricle is considered an extremely
malignant cell clusters that showed an invasive architectural     rare location. Salih et al reviewed 453 EPC cases, with 40%
pattern (Figure 2). Tumor cells were demonstrating marked         of these located on the head and neck, but 7 cases only on
nuclear pleomorphism and prominent nucleoli, they were            the ear [4]. The cases we encountered concerned male pa-
large polyhedral to cuboid with moderate to abundant eo-          tients exclusively, thus confirming the predilection of facial
sinophilic and more rarely clear cytoplasm, as well as many       EPC towards the male gender [5]. Misdiagnosis of EPC due
mitotic figures (up to 6-7/HPF). Other observed features          to its atypical presentation is highly probable. It could also
included squamous differentiation, without keratinization,        be attributed to the diversity of total number of sweat glands
ductal differentiation and focally desmoplasia. No tumor          on different parts of the body. However, current data an-
displayed granular cells or decapitated lumens, ruling out the    nul this idea, as EPC occurrence is not correlated with the



2                                                                     Original Article | Dermatol Pract Concept. 2022;12(2):e2022085
Figure 2. Eccrine Porocarcinoma – Histology. (A) Diffuse infiltrative pattern. (B) Duct formation, nuclear pleomorphism and prominent
nucleoli. (C) Immunohistochemical expression of CEA in ducts.


                                    Table 1. Characteristics of the EPC cases identified
           Month/           Age                                  Diameter         Surgical          Adjuvant
 Case       Year          (years)     Gender     Location          (mm)          Treatment          Treatment          Recurrence
   #1       5/2012          69           M       Cheek              13        Excision -pri-                -       In 6 months
                                                                              mary repair
   #2      11/2018          80           M       Lower lid          30        Excision - eye ex-   Radiotherapy     In 4 months
                                                                              enteration-tem-
                                                                              poralis flap
   #3      12/2019          84           M       Temple             10        Excision -FTSG                -       No
   #4       3/2021          61           M       Ear                22        Excision -postau-    Radiotherapy     No (5 months
                                                                              ricular flap                          postoperatively)
FTSG = full thickness skin grafting; M = Male.



                                                                         highest concentration of sweat glands (palmoplantar region)
                                                                         [5]. Underreporting of this entity remains also a possibility.
                                                                            It is proposed that EPC emerges either de-novo or from
                                                                         a pre-existing benign poroma [2]. The ratio of malignant
                                                                         transformation was estimated around 18% [2]. Immunosup-
                                                                         pression may be a contributing factor in EPC pathogenesis,
                                                                         as well as sun exposure [4]. Genetic predisposition may be
                                                                         also implicated, as p53 oncogene expression is witnessed in
                                                                         88% of cases, while loss of retinoblastoma protein and over-
                                                                         expression of p16 gene, though not consistent, have been
                                                                         also reported [6,7]. None of these implicating factors could
                                                                         be associated with a predilection for EPC manifestation on
                                                                         specific areas.
                                                                            From a clinical standpoint, EPC usually presents itself as
                                                                         an asymptomatic solitary nodule or mass which can progress
                                                                         to ulceration and cause pain [2]. The lesion is typically no-
                                                                         ticed over a long period of time (up to several years), although
                                                                         cases of rapid growth in a few months were also noted.
                                                                         Considering its rarity, EPC needs to be differentiated from
                                                                         a plethora of skin conditions such as seborrheic keratosis,
                                                                         pyogenic granuloma, amelanotic melanoma, squamous cell
 Figure 3. Eccrine Porocarcinoma – Locoregional metastasis of pa-        carcinoma and verruca vulgaris [2]. This task becomes even
 tient #2, 2 years following surgery and radiotherapy.                   harder for the dermatologist, as most of the aforementioned



Original Article | Dermatol Pract Concept. 2022;12(2):e2022085                                                                         3
skin lesions are encountered predominantly in older people,        of the patients with confirmed EPC of the face enabled the
while no clear clinical characteristics for EPC have been re-      analysis of such a rare malignancy, mitigating the potential
ported and thus clinical diagnosis often fails.                    effect of the study limitations to the outcomes of interest.
    The clinical characteristics of EPC act as an insurmount-          Overall, EPC is very rarely encountered. Based on this co-
able impediment to the clinical diagnosis and shifted focus        hort and the pertinent literature review, the evidence regard-
on the histological examination. The presence of cytologic         ing the pathophysiology, surgical and adjuvant treatment
atypia with advancing margin and poromatous basaloid               is inconclusive and call for further reporting and analysis.
cells displaying ductal differentiation confirmσ the diagno-       Currently, awareness should be raised by the clinician to
sis [2]. Robson et al has described 3 histological variants.       properly recognize EPC and treat promptly, and vigilance is
“Infiltrative” is characterized by ill-defined lower limits with   needed, due to its high malignant nature and mortality rates.
malignant clusters infiltrating the dermis and hypodermis,
“pushing” by well-defined lower dermal border, and “page-          Learning points
toid” by intraepidermal clusters of tumoral cells, mimicking
Paget disease [2]. Immunohistochemistry can be a significant       • Eccrine porocarcinoma (EPC) is an extremely rare sub-
diagnostic aid, including various stains for CEA, EMA, CK-7          type of non-melanoma skin cancer, mostly presenting in
and S-100 protein [8].                                               the extremities of the elderly population.
    EPC is regarded as a very aggressive malignancy ex-            • Underreporting and misdiagnosis of EPC occurring on the
hibiting high metastatic potential [2]. A 31% of regional            face are distinct possibilities accounting for its rarity.
or distant metastasis was revealed, with the most common           • Histologic examination confirms the diagnosis and iden-
sites being the regional lymph nodes (57.7%), and the lungs          tifies the histologic subtype, essential for guiding further
(12.8%) [4]. Mortality increases drastically in case of met-         treatment.
astatic disease, with overall survival ranging between 5 and       • EPC is regarded as a very aggressive malignancy exhibit-
24 months [5]. Local recurrence after excision is also high,         ing high rates of local recurrence and metastasis.
reaching 25%, with the “infiltrative” and “pagetoid” sub-          • Wide local excision remains the optimal treatment option,
types being implicated most often [2,9]. Indeed, 2 of our 4          without a clear treatment protocol established up to date.
patients manifested local recurrence few months following          • Vigilance is mandatory for prompt recognition and treat-
tumor excision. Multi-nodularity and ulceration are among            ment to avoid the high mortality rates reported.
the signs of aggressiveness, while pedunculated tumors are
less aggressive [4]. Lympho-vascular invasion, positive tu-
mor margins, high mitotic count (> 14/HPF) and tumor
                                                                   Acknowledgments
depth (> 7 mm) have been proposed as predictors of worse           The authors acknowledge the pathologist Dr. Aikaterini
clinical outcomes [2].                                             Zioga for her valuable assistance with the pathological data
    Currently, no established treatment guidelines exist. Wide     evaluation.
local resection with confirmation of clear margins remains
the optimal treatment option, achieving therapeutic outcome
in 70%-80% of cases [5]. Belin et al proposed a surgical           References
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Original Article | Dermatol Pract Concept. 2022;12(2):e2022085                                                                             5
