Surgical case reports
A Giant Proliferating Trichilemmal Tumor of the Perineum with Pelvic Extension: Transperineal Resection Facilitated by Cyst Fluid Redistribution and Enhanced Perineal Expansion
By Kojima M, Miyake T, Tani S and 10 others.
Abstract
Introduction
Proliferating trichilemmal tumor (PTT) is a rare neoplasm arising from the outer root sheath of the hair follicle and typically occurs on the scalp of elderly women. Perineal occurrence is extremely rare, and, to our knowledge, no giant perineal PTT extending into the retroperitoneal pelvic space has been previously reported.
Case presentation
A 77-year-old man presented with a giant perineal mass that had gradually enlarged over 10 years and rapidly increased in size during the preceding 2 years. CT and MRI demonstrated a 35 cm dumbbell-shaped cystic lesion extending from the perineum into the retroperitoneal pelvic space, with papillary projections arising from the cyst wall. Malignant transformation could not be ruled out preoperatively. Tumor resection was achieved through the transperineal approach, facilitated by gravitational redistribution of the cystic contents and expansion of the perineal component, followed by laparoscopic inspection confirming no intra-abdominal or pelvic injury. Histopathological examination demonstrated trichilemmal keratinization without cytological atypia or evidence of malignancy, leading to a diagnosis of benign PTT. The postoperative course was uneventful.