Malignant mesothelioma of the tunica vaginalis testis: review of the literature and assessment of prognostic parameters.

BACKGROUND: Only 73 cases of malignant mesothelioma of the tunica vaginalis testis have been reported in the last 30 years. Although these tumors were most often seen in patients between ages 55 and 75 years, 10% of the patients were younger than 25 years. Because prognostic parameters have not yet been reported, the authors present another case of a male age 14 years and a review of the available literature, which they conducted to determine prognostic parameters.
METHODS: The medical literature about malignant mesothelioma of the tunica vaginalis testis was reviewed. For the determination of prognostic parameters, a univariate and multivariate Cox regression model was used to assess the relevance of the patient's age, history of asbestos exposure, tumor histology, primary therapeutic approach, and presence of metastatic disease to survival.
RESULTS: Previous exposure to asbestos or asbestos-containing materials must be considered a risk factor for the development of malignant mesothelioma. The major difficulty in managing patients with malignant mesothelioma of the tunica vaginalis testis was determining an accurate preoperative diagnosis, which was reported in only two cases. Due to the lack of characteristic symptoms, 97.3% of the cases were diagnosed intraoperatively. Of patients who underwent local resection of the hydrocele wall, 35.7% experienced local tumor recurrence, as compared with 10.5% after scrotal orchiectomy and 11.5% after inguinal orchiectomy. Therefore, radical orchiectomy should be the first-line therapy. The median survival of the patients was 23 months, which decreased to 14 months in cases of recurrence. The overall recurrence rate (local and disseminated) was 52.5%. More than 60% of recurrences developed within the first 2 years of the follow-up. In some cases of disseminated mesothelioma, adjuvant chemotherapy or radiotherapy was given. Although reports on adjuvant treatments were limited, radiotherapy appeared to be more effective than chemotherapy. However, 37.9% died of disease progression. Assessment of prognostic parameters revealed a significant correlation of patient's age with survival (P < 0.01), with a better outcome for younger patients and a worse disease course for patients with primary disseminated disease (P < 0.05) in univariate analysis. A multivariate Cox regression model of prognostic parameters concerning survival did not yield statistically significant results.
CONCLUSIONS: Malignant mesotheliomas of the tunica vaginalis testis rarely occur, but the possibility should be considered for all age groups. Univariate analysis determined that a patient's age and the presence of primary disseminated disease were prognostic parameters related to survival. Due to the invasive potential of this disease and the risk of tumor recurrence, radical orchiectomy and close follow-up are strongly recommended.