To describe clinical management and outcomes of a cohort of patients with malignant mesothelioma of the tunica vaginalis testis (MMTVT) who received treatments beyond radical orchiectomy.

Patients with confirmed MMTVT at a single tertiary care institution were identified. Treatments, pathologic outcomes, and survival were recorded. Prognostic variables associated with survival were analyzed with a Cox proportional hazards model and Kaplan-Meier curves.

Overall, 15 patients were included. Initial presentation was a scrotal mass in 7 of 15 (47%) and hydrocele in 5 of 15 (33%) patients. Clinical staging revealed enlarged nodes in 5 of 15 (33%) patients. Radical orchiectomy was the initial treatment in 5 of 15 (33%) patients. Positive surgical margins were found in 6 of 14 (43%) radical orchiectomies and were associated with worse survival (P = .007). The most frequent histologic subtype was epithelioid, associated with better survival (P = .048). Additional surgeries were performed on 12 of 15 (80%) patients. Pathologic examination revealed MMTVT in 6 of 12 (50%) hemiscrotectomies, 7 of 8 (88%) retroperitoneal lymph node dissections, 1 of 7 (14%) pelvic lymph node dissections, and 10 of 10 (100%) groin dissections. Five patients received adjuvant chemotherapy. Two also received adjuvant radiation therapy. Three patients with lymph node involvement remain no evidence of disease over 6 years after diagnosis. After a median follow-up of 3.5 years (interquartile range: 1.2-7.2), 5 patients have died, all of MMTVT; the median overall survival has not been reached. Common sites of relapse were lungs (5 of 7) and groin (3 of 7).

The pattern of metastatic spread of MMTVT is predominantly lymphatic. Nodes in the retroperitoneum and the groin are commonly involved. Prognosis is poor, but there may be a role for aggressive surgical resection including hemiscrotectomy, and inguinal and retroperitoneal lymph nodes.