10.5826/dpc.1201a21
text/xml
2160-9381
1753
en
Nicola Di Meo
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
dermoscopy
Rosette-like Structure: A Main Dermoscopic Feature in a Small Trichilemmal Cyst
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2022-02-02
2021-04-12
2022-02-02
2022-02-09
e2022021
Dermatol Pract Concept
Nicola Di Meo
2022/02/02
10.5826/dpc.1201a21
e2022021
Dermatology Clinic, Maggiore Hospital, University of Trieste, Trieste, Italy
2160-9381
dermoscopy
en
e2022021
Haspeslagh M, Noë M, De Wispelaere I, et al. Rosettes and other white shiny structures in polarized dermoscopy: histological correlate and optical explanation. J Eur Acad Dermatology Venereol. 2016;30(2):311–313. DOI: 10.1111/jdv.13080. PMID: 25786770.
Rosette-like Structure: A Main Dermoscopic Feature in a Small Trichilemmal Cyst
https://dpcj.org/index.php/dpc/article/download/1753/1473
                    Dermatology Practical & Conceptual


Rosette-like Structure: A Main Dermoscopic Feature
            in a Small Trichilemmal Cyst
            Giulia Bazzacco1, Enrico Zelin1, Carlo Alberto Maronese2, Vittorio Ramella3,
                         Diego Signoretto4, Iris Zalaudek1, Nicola Di Meo1


1 Dermatology Clinic, Maggiore Hospital, University of Trieste, Trieste, Italy
2 Dermatology Unit, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
3 Plastic Surgery Department, Cattinara Hospital, ASUGI, Trieste, Italy
4 Pathological Anatomy and Histology Department, Cattinara Hospital, University of Trieste, Trieste, Italy.



Key words: trichilemmal cyst, rosette, dermoscopy
Citation: Bazzacco G, Zelin E, Maronese CA, et al. Rosette-like structure: a main dermoscopic feature in a small trichilemmal cyst.
Dermatol Pract Concept. 2022;12(1):e2022021. DOI: https://doi.org/10.5826/dpc.1201a21
Accepted: May 26, 2021; Published: January 2022
Copyright: ©2022 Bazzacco 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 and approved the final version of the submitted paper. NDM and
IZ defined the design and intellectual content of the paper. GB searched for literature, wrote the draft, edited the manuscript and the tables,
preparing them for submission. EZ, CAM, and VR reviewed the article with consistent integrations. DS analyzed the histology samples and
contributed to image collection.
Corresponding author: Enrico Zelin, MD, Dermatology Clinic, Hospital Maggiore, Trieste, Italy. E-mail address: enrico.zelin@gmail.com




Introduction                                                             eyebrow that relapsed after treatment with cryotherapy, in
                                                                         absence of other skin lesions (Figure 1A). On dermoscopy,
Trichilemmal cysts (TCs), also called pilar cysts, represent the         shiny white areas arranged as a four-leaf clover (rosette-like
second most common type of cutaneous cysts, after epidermal              structure) with a minimal erythematous background was
ones [1]. TCs most commonly occur in middle-aged women                   seen (Figure 1B). The lesion was excised, and histopatholog-
and have a predilection for the scalp but can occasionally               ical examination indicated a multilayer cystic neoformation
show different locations. They appear as solitary or multiple            with eosinophilic cells positive for high molecular weight
intradermal palpable papules/nodules, occurring as sporadic              cytokeratin (CK34Be12+) and absence of the granular layer,
lesions or in hereditary/familial settings with autosomal dom-           consistent with the diagnosis of TC (Figure 2, A-C).
inant transmission [1]. From a histological point of view, TCs                On clinical examination, TCs appear as smooth, mobile,
have an undulating epithelial wall with no granular layer and            firm, dermal or subcutaneous papules or nodules with a
a compact keratinization and reveal an isthmic origin [1].               typical diameter of 10-20 mm. They do not characteristi-
                                                                         cally present visible pores [1]. Dermoscopy usually shows a
                                                                         pinkish-yellow or homogeneous yellowish-white area with
Case Presentation
                                                                         a peripheral erythematous halo and sometimes, due to the
A 36-year-old woman was referred to our clinic with an                   Tyndall effect, the keratin material appears blueish [1]. In
asymptomatic papule of 1 mm in diameter above her right                  the present case, the TC was very small (1 mm papule) and




Research Letter | Dermatol Pract Concept. 2022;12(1):e2022014                                                                                1
showed a white shiny rosette-like structure on dermoscopic           Conclusions
evaluation. In the literature, the precise morphological cor-
relate of rosettes is not known, since they are not specific         Differential diagnosis of TCs can include various entities,
and can be seen in various cutaneous lesions, mainly in              such as other cystic lesions but also basal cell carcinoma,
actinic keratoses, basal cell carcinomas and squamous cell           squamous cell carcinoma, sebaceous hyperplasia and syrin-
carcinomas, and rarely in cysts. This rosette-like pattern can       goma (Table 1) [2]. Moreover, these cysts can be subject to
be probably caused by horny material in the adnexal opening          inflammation, infection, and enlargement, but rarely grow
or by concentric perifollicular fibrosis [2].                        more extensively, forming proliferating TCs (adnexal tumors




Figure 1. Clinical and dermoscopic appearance of the trichilemmal cyst. (A) A small 1-mm papule above the eyebrow of the patient.
(B) Dermoscopy shows shiny white areas arranged as a four-leaf clover (rosette-like structure) with a minimal erythematous background.




                                                                     Figure 2. Histopathological features of the trichilemmal cyst. (A)
                                                                     Global appearance of the multilayer cystic neoformation, H&E,
                                                                     × 10. (B) Eosinophilic cells and absence of granular layer, H&E,
                                                                     × 40. (C) Cells showing positive immunohistochemistry stain for
                                                                                                                  +×
                                                                     high molecular weight cytokeratin CK34Be12 , 40.


2                                                                        Research Letter | Dermatol Pract Concept. 2022;12(1):e2022014
     Table 1. Dermoscopic Clues That Differentiate Trichilemmal Cyst from its Main Differential
                                            Diagnoses
                            Lesion                                                 Classic Dermoscopic Criteria
 Trichilemmal cyst                                              Pinkish-yellow or homogeneous yellowish-white background
                                                                Peripheral erythematous halo
                                                                Absence of pore sign
                                                                Blue pigmentation (Tyndall effect of keratin)
 Epidermal cyst                                                 Yellowish-white papule
                                                                Pore sign: keratin-filled, circular orifice, whitish, yellow, brown
                                                                or black in color
                                                                Wobble sign (movement of the lesion with respect to the
                                                                surrounding tissues, except for the pore, which represents the
                                                                site of anchorage of the cyst)
 Basal cell carcinoma                                           Arborizing vessels, sort fine telangiectasias Ulceration, erosions
                                                                Maple-leaf like, spoke-wheel and concentric structures
                                                                Blue-gray globules, blue-ovoid nests
 Squamous cell carcinoma                                        Presence of keratin, especially in conjunction with blood spots
                                                                Coiled vessels
                                                                White structureless zones, white circles (highly differentiated
                                                                SCCs)
                                                                Predominantly red color, bleeding and ulcerations (poorly
                                                                differentiated SCCs)
 Syringoma                                                      Yellowish-brownish structures
                                                                Structureless background
                                                                Reticular vessels
 Sebaceous hyperplasia                                          Central umbilication surrounded by aggregated polylobular
                                                                white-yellowish structures (cumulus sign); this global
                                                                appearance is known as bonbon toffee sign
                                                                Surrounding crown of vessels at
                                                                the periphery

SCC = squamous cell carcinoma.



usually with a benign behavior) or may even undergo malig-          Informed consent: Written informed consent for publication
nant transformation. Therefore, when there is suspicion of          of her clinical details and clinical images was obtained from
TC, it is appropriate to proceed to radical surgical excision       the patient.
with histological examination in order to exclude malignant
tumors and prevent complications.
   In conclusion, dermoscopy represents a noninvasive tool
                                                                    References
that allows the identification of specific morphological fea-        1. Gencoglan G, Karaarslan IK, Akalin T, Ozdemir F. Trichilemmal
tures in different skin tumors. It significantly improves the           cyst with homogeneous blue pigmentation on dermoscopy. Aus-
early diagnosis of cutaneous lesions and helps in choosing the          tralas J Dermatol. 2009;50(4):301–302. DOI: 10.1111/j.1440-
                                                                        0960.2009.00566.x. PMID: 19916979.
best treatment options for each case based on the suspected
                                                                     2. Haspeslagh M, Noë M, De Wispelaere I, et al. Rosettes and other
diagnosis. In this article, we described a very characteristic
                                                                        white shiny structures in polarized dermoscopy: histological
dermoscopic pattern associated with a small TC. The prompt              correlate and optical explanation. J Eur Acad Dermatology Ve-
surgical treatment and subsequent histopathological exam-               nereol. 2016;30(2):311–313. DOI: 10.1111/jdv.13080. PMID:
ination aided in a diagnosis of certainty and in prevented the          25786770.
growth of this lesion that was localized to an aesthetic area.




Research Letter | Dermatol Pract Concept. 2022;12(1):e2022014                                                                        3
