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206 rev port estomatol med dent cir maxilofac. 2019;60(4):205-209

Triquilemoma da região perioral – Caso clínico

r e s u m o

Palavras-chave: O triquilemoma é um tumor benigno dos anexos cutâneos, traduzindo uma proliferação
Síndrome de Cowden hamartomatosa das células dos folículos pilosos. Resulta da multiplicação de células claras
Triquilemoma desmoplásico ricas em glicogénio e origina, habitualmente, uma lesão exofítica papular ou nodular. Podem
Carcinoma triquilemal surgir lesões únicas ou múltiplas, associadas, neste caso, à síndrome de Cowden. O triqui-
Triquilemoma lemoma desmoplásico é uma variante histológica que pode simular um carcinoma invasivo,
como os carcinomas triquilemal, basocelular ou pavimentocelular. Será descrito um caso
clínico de um doente do sexo masculino, com 68 anos, que foi referenciado para um cirurgião
oral pelo seu higienista por apresentar uma pápula ulcerada, assintomática, na região pe-
rioral. A lesão foi alvo de biópsia excisional, tendo o exame anatomopatológico revelado
tratar-se de um triquilemoma convencional. O controlo periódico do doente foi realizado
um ano depois, não tendo sido observada qualquer recidiva da lesão. (Rev Port Estomatol
Med Dent Cir Maxilofac. 2019;60(4):205-209)
© 2019 Sociedade Portuguesa de Estomatologia e Medicina Dentária.
Published by SPEMD. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).

of clear cells from the root of the hair follicle, usually with a
Introduction
large connection to the epidermal surface. 2,3,5 The cells’ pale
Trichilemmoma was first described in 1962 by Headington appearance is due to the accumulation of glycogen inside
and French, in their treatise on the histogenesis and classifi- them and can be evidenced by periodic acid-Schiff (PAS)
5
cation of primary neoplasms of the hair follicle, as a benign staining. A papillomatous surface is common, reflecting the
5
solid cutaneous epithelial tumor composed of clear cells, presence of verrucous hyperplasia with hypergranulosis. Pe-
1
with differentiation toward the outer hair root sheath. It is a ripherally, each lobe also has a small and compact layer of
hamartomatous proliferation arising from glycogen-rich epi- columnar cells arranged in palisade, formed by keratinocytes,
thelial cells. 2 usually with a thick adjacent basement membrane. 3,5 As a
Trichilemmomas can be solitary or multiple. The single sign of their differentiation into the hair follicle’s outer root
presentation is usually found on the face of adults or the sheath, trichilemmomas express CD34, a feature that has been
elderly, as a small papule or nodule, similar in color to the used to distinguish them from other epithelial tumors through
underlying skin or slightly erythematous, with a smooth or immunohistochemical analysis. 11-13
warty surface. It sometimes exhibits central ulceration as well In 1990, Hunt and colleagues described a rare histological
as keratinization of the epidermal surface, which may be suf- variant of trichilemmoma that contains areas of narrow irreg-
ficient for the formation of pearls or a cutaneous horn. It ular cords of epithelial cells trapped in a dense eosinophilic
3,4
may also involve other locations, such as the neck, scalp, tho- hyaline stroma resembling an invasive carcinoma and called
2,3
racic skin or vulva. It presents a slow, progressive growth, it desmoplastic trichilemmoma. It is predominant in women
14
and the evolution over time can vary from months to years, after the fifth decade of life. 15,16
with its diameter rarely exceeding 1 cm. 5 Another relevant condition is the trichilemmal carcinoma,
The presence of multiple facial trichilemmomas is associ- initially known as clear cell carcinoma of the skin, which is a
ated with Cowden syndrome, originally described by Costello malignant neoplasm that combines trichilemmal keratiniza-
6
in 1940 and named by Lloyd and Dennis in 1963. In 1972, Wea- tion with atypical changes such as intense mitotic activity,
ry and colleagues described several distinctive mucocutane- reticular dermis invasion and ulceration. 17-21
ous features, such as hamartomatous lesions of ectodermal, The differential diagnosis of trichilemmoma includes
mesodermal and ectodermal origin, and proposed the desig- other epidermal or hair follicle tumors, namely trichofollicu-
7
nation “multiple hamartoma syndrome.” Later, in 1977, loma, fibroma, inverted follicular keratosis, seborrheic kerato-
Brownstein and colleagues suggested cutaneous trichilemmo- sis, intradermal melanocytic nevus and keratoacanthoma. 22-25
8,9
mas as a specific marker of this condition. The diagnostic Lesions associated with human papillomavirus such as
criteria were reviewed at an international consensus meeting wart vulgaris or squamous papilloma should also be taken
26
that established that the main pathognomonic lesions consist into account. Trichilemmal carcinoma, basal-cell carcinoma
of multiple cutaneous papules, papillomatous alterations of and squamous-cell carcinoma are malignant entities that
the oral mucosa corresponding to fibromas, as well as palmar should integrate the differential diagnosis of desmoplastic
or plantar acral keratosis. 10 trichilemmoma. 14,26
Histopathologically, trichilemmomas are small and cir- The treatment of trichilemmomas consists of surgical ex-
cumscribed lobular or multilobular proliferations, consisting cision, being the recurrence rare, which contributes to a good