Pleural mesothelioma with cutaneous extension to chest wall scars

Background: Cutaneous mesothelioma is rare but may occur following local surgical procedures for visceral mesothelioma or as a metastasis. Methods: A patient with pleural mesothelioma, who developed papules within chest wall scars, 14 and 15 months after pleural biopsy and thoracentesis, respectively, is reported. Results: Histopathology showed an epithelioid tumor forming tubulopapillary and glandular structures. The diagnosis of mesothelioma was confirmed with immunohistochemistry. Tumor cells stained characteristically for low-molecular-weight cytokeratins 5/6, calretinin, and vimentin and were negative for mucicarmine, carcinoembryonic antigen, thyroid transcription factor 1, prostate-specific antigen, gross cystic disease fluid protein, S-100, factor VIII, and CD31. Conclusions: Histologically, mesothelioma may resemble a primary adnexal neoplasm, metastatic adenocarcinoma, or angiosarcoma. Immunohistochemistry can clarify the diagnosis. Clinicians should be aware of the varied presentations of mesothelioma, as cutaneous presentations are becoming increasingly common.