Malignant mesothelioma of tunica vaginalis testis: a case report
Mesothelioma of the tunica vaginalis testis is a extremely rare tumor and the most unusual type of mesothelioma with only a limited number of reported cases (less than 300 cases published in the literature) . Because of his low incidence and nonspecific clinical presentation, it’s almost diagnosed accidentally during surgery for other reasons and the prognosis is usually poor. We present a case of a patient with a mesothelioma of tunica vaginalis testis, diagnosed secondarily during hydrocele surgery, with long-term survival after radical surgery.
Materials and Methods
we describe a case of a 40 years old patient, who was admitted to our department for routine left hydrocele surgery. The patient reported progressive scrotal enlargement without pain and the ultrasonography showed a simple left hydrocele with 350 ml in volume and normal testis. During the operation an anatomopathological analysis was request because of the strange nodular thickening of tunica vaginalis: the examination revealed a malignant mesothelioma with epithelioid structure and tubule-papillary proliferation.
The patient agreed with a radical operation and a left hemiscrotectomy with left inguinal lymph node dissection was performed. The definitive histology confirmed the previous report of malignant mesothelioma with angioinvasion but normal testicle findings and negative lymph node. The immunoistochemical study showed positivity for calretinin, cytocheratin 5/6 and WT1 while carcinoembryonic antigen was negative. The patient underwent further examinations: computed tomography (CT) showed absence of lymph node enlargement or distant metastases. Chemotherapy and radiotherapy were not indicated. For the first 2 years a CT was repeated every 4 months, and then every 6 months for 3 years. Five years after surgery the patient has well done and show no signs of residual disease.
Mesothelioma is a rare malignant tumor, that develops from the internal surface of the pleura, pericardium, peritoneum and tunica vaginalis testis. Less then 5% of cases of malignant mesothelioma occur in the tunica vaginalis . The first case was described by Barbera and Rubino in 1957 . Due to his low incidence, it is unknown whether asbestos exposure plays a role in his etiology: less than half of reported mesothelioma of tunica vaginalis testis are associated with asbestos exposure. Other suspected causes are scrotal trauma, log-term hydrocele, herniorraphy and exposition to radiation during radiotherapy. The diagnosis occurs often secondarily during surgery for other reasons (hydrocele, testicular tumor or inguinal hernia). Approximately one third of tumors is locally invasive when diagnosed and more of 50% of patients develop a local recurrence with most recurrences within the first 2 years . Because radiotherapy and chemotherapy have failed to provide significant results, a radical resection with hemiscrotectomy, even with local lymphadenectomy, appears to be the preferred treatment, associated with better prognosis and should be proposed when possible. Our case shows the importance of a correct diagnosis, if possible preoperative otherwise intraoperatively in case of fibrotic thickening of the tunica vaginalis or hemorrhagic hydrocele fluid. A mesothelioma of tunica vaginalis testis should be suspected always in all patients with asbestos exposure and rapid enlargement of hemiscrotum.
malignant mesothelioma of the tunica vaginalis testis is a rare entity, often initially thought to be a hydrocele or an epididymal cyst. An aggressive approach with hemiscrotectomy with or without regional lymphadenectomy can reduce the risk of recurrence.
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