D'Avila Denise Graffitti, Kanno Danilo Toshio, de Castilho da Silva Daniel, Pastro Vitor Rafael, Novelli Paula Cristina Stefen, de Paula Freitas Bruna Zini, Martinez Carlos Augusto Real
University Hospital São Francisco de Assis na Providência de Deus, Bragança Paulista, São Paulo, Brazil.
University Hospital São Francisco de Assis na Providência de Deus, Bragança Paulista, São Paulo, Brazil; UNICAMP, Campinas, São Paulo, Brazil.
Int J Surg Case Rep. 2018;53:175-178. doi: 10.1016/j.ijscr.2018.09.049. Epub 2018 Oct 18.
Proliferating trichilemmal cysts (PTCs) are rare benign neoplasms originating from the follicular isthmus. They can undergo trichilemmal keratinization and malignant degeneration to form epidermoid carcinoma. They occur on the scalp in more than 90% of patients and are more common in elderly women.
A 56-year-old woman complained of perianal discomfort upon sitting. She presented with a perianal nodule of approximately 3 cm in diameter that had exhibited slow and progressive growth over 8 years. After surgical excision of the lesion with safety margins, histopathological examination showed that it was a proliferating trichilemmal cyst in the perianal region.
There are no reports in the literature on PTC in the perianal region. The location with the highest prevalence is the scalp; other sites of occurrence are the neck, trunk, underarms, pubis, vulva, lower and upper limbs, upper lip, and gluteal region.
The development of PTC in the perianal region is an exceptional occurrence, and when it does occur, surgical treatment should always be indicated because of the risk of malignant degeneration to form epidermoid carcinoma.
增殖性外毛根鞘囊肿（PTC）是起源于毛囊峡部的罕见良性肿瘤。它们可发生外毛根鞘角化和恶性变，形成表皮样癌。超过90%的患者发生于头皮，且在老年女性中更为常见。
一名56岁女性主诉坐下时肛周不适。她有一个直径约3厘米的肛周结节，在8年里呈缓慢渐进性生长。在对病变进行带安全切缘的手术切除后，组织病理学检查显示其为肛周区域的增殖性外毛根鞘囊肿。
文献中尚无关于肛周区域PTC的报道。发病率最高的部位是头皮；其他发生部位包括颈部、躯干、腋窝、耻骨、外阴、下肢和上肢、上唇以及臀区。
肛周区域发生PTC是一种特殊情况，一旦发生，由于存在恶性变形成表皮样癌的风险，通常应进行手术治疗。
