Malignant mesothelioma of the tunica vaginalis testis: A rare, enigmatic tumor

Malignant mesothelioma of the tunica vaginalis is a rare urologic tumor with fewer than 100 cases reported in the literature. Patients can present at any age with nonspecific symptoms. A typical sonographic appearance of paratesticular papillary excrescence or nodularity typically leads to a preoperative diagnosis of hydrocele or testicular tumor. Following diagnostic intraoperative frozen sample analysis, radical orchiectomy is recommended. Recent advances in Doppler sonography allow hypovascularity or hypervascularity of paratesticular nodules to be identified. These characteristics are suspicious for malignant mesothelioma, which potentially assists in preoperative diagnosis. The current case depicts a 37-year-old male with a 1-week history of subtle testicular enlargement. He was diagnosed with malignant mesothelioma of the tunica vaginalis following scrotal excisional biopsy. Literature is discussed relative to patient demographics, diagnostic and management issues, prognosis, and follow-up guidelines.