Somatic DICER1-mutated Sertoli-Leydig cell tumor in a postmenopausal woman: eight years of peritoneal relapse managed with cytoreductive surgery and HIPEC - a case report.

Sertoli-Leydig cell tumors are rare ovarian sex cord-stromal tumors that usually arise in young women and are often hormonally active. Intraperitoneal dissemination and relapse are uncommon, and recurrence patterns in postmenopausal women are poorly characterized. This report describes a 55-year-old postmenopausal woman with a poorly differentiated, estrogen receptor-negative, non-functional Sertoli-Leydig cell tumor. Despite adjuvant platinum-based chemotherapy, she relapsed within one year. Over eight years her disease followed a pattern of recurrent intraperitoneal dissemination, managed with multiple cytoreductive procedures, including three with heated intraperitoneal chemotherapy. Somatic molecular profiling identified a DICER1 mutation without a germline alteration. Systemic therapies, including platinum-based chemotherapy and immune checkpoint inhibition, produced only transient disease control, and repeated surgery, rather than systemic therapy, was the mainstay of management. The case illustrates an aggressive, somatic DICER1-mutated tumor arising outside the usual age range, and suggests that such tumors can behave aggressively in older women, in whom systemic therapy has limited efficacy and management is necessarily multidisciplinary.