Malignant Mesothelioma of Tunica Vaginalis Testis: Macroscopic and Microscopic Features of a Very Rare Malignancy

Malignant mesothelioma of the tunica vaginalis testis (MMTVT) is an extremely rare tumour, usually mimicking benign pathologies of the scrotum. Our case is an 84-year-old male patient who appealed with a painless, left-sided scrotal swelling longer than 2 months. Although the level of tumour markers was normal, ultrasonographic examination results forced us to perform an inguinal scrotal exploration. Multiple small papillary tumours, both on tunica vaginalis and tunica albuginea, were detected intraoperatively. Due to these findings, radical orchiectomy was performed. A pathological evaluation showed malignant mesothelioma (MM) of the tunica vaginalis testis. Exposure to asbestos is a well-known risk factor. Furthermore, a history of trauma, herniorrhaphy and chronic hydroceles is blamed as a possible risk factor. Scrotal ultrasonography is the mainstay of primary diagnosis and, therefore, it should not be overlooked when dealing with benign scrotal cysts or hydroceles, which are very common pathologies at these decades, too. Radical inguinal orchiectomy is the primary treatment choice for localised MMTVT disease, whereas in signs of lymph node metastasis, inguinal lymph node dissection is required. Radical resection should be completed with chemotherapy and/or radiotherapy for an advanced or recurrent disease. This case, which is very rarely reported in the literature and detected during inguinal exploration, along with the pathological works that supported the diagnosis, was presented with this report.