Atypical presentation of testicular mesothelioma

Mesothelioma is a rare cancer that generally affects the lining of the lungs. However, in more rare cases, there are extra-pleural involvement of organs that are lined with mesothelial cells, including the testicle. Mesothelioma of the tunica vaginalis of the testicle typically presents with a painless scrotal mass with accompanying hydrocele of the affected side. The most common predisposition to mesothelioma of the tunica vaginalis is previous asbestos exposure, long-standing hydrocele, and previous scrotal surgeries. In this case we present a patient with isolated left tunica vaginalis mesothelioma of the testicle, yet without classic risk factors or other sites of disease. Left radical orchiectomy was performed and subsequent follow-up imaging did not reveal any sites of recurrence or metastasis. Although, mesothelioma of the tunica vaginalis is a rare cancer, it should be seen as a possible differential when evaluating new testicular masses.