Malignant mesothelioma of tunica vaginalis testis.

A case of biphasic malignant mesothelioma of the tunica vaginalis occurring in a sixty-four-year-old man is described. The tumor metastasized widely and led to the patient's death two and one-half years after diagnosis. Review of the literature revealed 7 cases of malignant mesothelioma of tunica vaginalis. These tumors appeared highly aggressive with early onset of metastasis. Histologically, the tumors may be epithelial, fibrous, or biphasic. In contrast to the benign variants of mesotheliomas, these tumors often show significant nuclear atypia, mitotic activity, and invasion of the epididymis, spermatic cord, lymphatic spaces, or the fibrous tissue of the tunica.