Malignant mesothelioma of the tunica vaginalis testis: A case report.

Malignant mesothelioma of the tunica vaginalis testis (MMTVT) is a rare pathological entity. The present report describes the case of a patient who presented with insidious-onset right lower abdominal pain and was diagnosed via histopathological examination following a radical right orchidectomy. After 7 months, the patient developed a palpable mass along the spermatic cord, which prompted a laparoscopic retroperitoneal lymph node dissection combined with an inguinal tumor resection. Adjuvant chemotherapy with pemetrexed and cisplatin was administered thereafter. At 9 months after the initial surgery, a groin mass was surgically excised, with pathology revealing fibroinflammatory changes. The patient remained under close surveillance without evidence of recurrence. Radiation therapy was initiated at 13 months post-surgery but was temporarily discontinued due to adverse effects. Given the current absence of standardized treatment guidelines for MMTVT, radical surgical resection combined with adjuvant radiotherapy or chemotherapy remains the mainstay of therapy, with the inguinal approach being the most commonly employed technique. Given the validated efficacy of immunotherapy in certain rare diseases and pleural mesothelioma, it may represent a promising therapeutic alternative for MMTVT patients whose pathological immunohistochemistry meets eligibility criteria and who have failed standard adjuvant radiotherapy and chemotherapy.