Unexplained Inguinal Adenopathy Leading to the Diagnosis of Metastatic High-Grade Serous Ovarian Carcinoma.

High-grade serous ovarian carcinoma (HGSOC) is the most common subtype of ovarian cancer, most commonly originating from the epithelium of the fallopian tube. In metastasis of HGSOC cells, there is a particular predilection for the omentum. Metastatic involvement of extraperitoneal lymph nodes, particularly the inguinal region, is rare and may pose a diagnostic challenge. We report a case of an 87-year-old female patient presenting with a right inguinal mass, in whom the pathology of the surgically removed mass confirmed the diagnosis of metastatic HGSOC, requiring oncological follow-up and management. This atypical pattern of spread underscores the importance of considering a Müllerian primary in the differential diagnosis of unexplained inguinal adenopathy and highlights the role of histopathology and immunohistochemistry in establishing the correct diagnosis.