Pediatric mesotheliomas are rare and their pathogenesis remains undefined. In this study, we report 5 cases of malignant mesothelioma in children, characterized by fusions involving the anaplastic lymphoma kinase (ALK) gene. Four cases occurred in females involving the abdominal cavity and were characterized by a pure epithelioid morphology. The fifth arose in the tunica vaginalis of a 15-year-old male and displayed a biphasic epithelioid-sarcomatoid phenotype. All cases demonstrated the classic morphologic and immunohistochemical features of malignant mesothelioma, including tubulopapillary architecture and cuboidal epithelioid cells with eosinophilic cytoplasm and uniform nuclei with vesicular chromatin. Immunohistochemically, all cases showed labeling for ALK, cytokeratins, WT1, and calretinin, while lacking expression of adenocarcinoma immunomarkers. Four cases demonstrated weak-moderate labeling for PAX8 protein, which resulted in diagnostic challenges with primary peritoneal sero..... READ ARTICLE
The American Journal of Surgical Pathology DOI:10.1097/PAS.0000000000001656
Authors: Argani, Pedram, Lian, Derrick W.Q., Agaimy, Abbas, Metzler, Markus, Wobker, Sara E. Matoso, Andres, Epstein, Jonathan I., Sung, Yun-Shao; Zhang, Lei and Antonescu, Cristina R