Molecular Characterization of Testicular Mesothelioma and the Role of Asbestos as a Causative Factor

* Context.--Mesothelioma of the tunica vaginalis testis (TVT) is an extremely rare form of mesothelioma. Objective.--To compare the clinical and molecular characteristics of mesothelioma of the TVT with those of mesothelioma at other more common sites, including the relationship with exposure to asbestos. Design.--We present clinical and pathological data for 9 cases of primary TVT mesothelioma. We performed whole-genome sequencing on 3 cases for the first time. Results.--The majority (7 of 9 cases) of TVT mesotheliomas were epithelioid, with the remaining 2 cases showing biphasic morphology. Morphology and immunohistochemical profiles were indistinguishable from mesothelioma elsewhere. Asbestos exposure was documented for 7 of the 9 cases, with no information for 2 cases. The 3 TVT mesothelioma cases that underwent whole-genome sequencing displayed a mutational profile similar to that of mesothelioma at other sites, including NF2 and TP53 mutations. Conclusions.--The clinical and molecular profile of TVT mesothelioma is similar to that of mesothelioma elsewhere. (Arch Pathol Lab Med. 2023;147:1446-1450; doi: 10.5858/arpa.2022-0283-OA)
Mesothelioma is a malignancy arising in the mesothelial cells lining serosal surfaces, most frequently occurring in the pleural (>80%) or peritoneal cavities (10%-15%). Exposure to asbestos is recognized as the [...]