A proliferating trichilemmal cyst in the perianal region: A case report

Abstract

HighlightsProliferating trichilemmal cyst is a rare benign neoplasms from the hair follicles.There are no reports of proliferating trichilemmal cyst in the perianal region.The treatment for trichilemmal cyst is surgical excision with normal tissue margins.The differential diagnosis of trichilemmal cyst include squamous cell carcinoma.

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“…Clinical manifestations are multiple, mimicking basal or squamous cell carcinomas, keratoacanthomas and nodular melanomas [2]. The diagnosis of trichilemmal carcinoma is established by means of histopathological examination in and the presence of abnormal mitoses, high mitotic rate, marked cellular pleomorphism, cytologic and architectural atypia, infiltrating margin, necrosis, and aneuploidy [3].…”

“…Trichilemmal carcinoma may exhibit aggressive invasion, even intracranially, causing considerable morbidity and even mortality [3,4].…”

Pilar cyst on the dorsum of hand

“…[ 8 – 10 ] In addition, infection of the human papilloma virus may be related to the pathogenesis of pilar cyst. [ 9 ] In very rare cases, pilar cyst can develop into malignant proliferative lump which clinically present as progressively enlarged lobulated masses, similar to squamous cell carcinoma. [ 11 ] It is very important to distinguish pilar cysts from proliferating pilar cysts, [ 12 ] since the later can undergo malignant transformation.…”

Rare Presentation of Pilar Cyst of the Thumb

“…A previously held notion proposed that they could not arise in the palms and soles, 9 however, it is no longer found to be true. There have been three reported cases of pilar cysts on the hand previously, 10 - 13 but all of these lesions were present in the finger tips. They all arose in the non-hair bearing skin of the hand and in finger tips only.…”

“…Apart from the hand, they are also reported to arise in the anal region, 13 penile region 14 and around the eyes. 7 , 8 The pathogenesis of these cysts in the perianal region was thought to develop on the wall of a previous hair follicle cyst as a result of trauma or inflammation.…”