Rare Diagnosis of Malignant Mesothelioma in a Young Patient with Rheumatoid Arthritis

Malignant pleural mesothelioma is an aggressive malignant neoplasm of the pleural layer associated with asbestos exposure that has a poor prognosis. Studies of malignant pleural mesothelioma in younger cohorts show decreased association with asbestos exposure, longer survival, and overall improved prognosis. Immunohistochemical markers, including calretinin, WT-1, CK5/6, and most recently BAP-1, aid in the pathological diagnosis of the disease. Presented here is the rare case of a young woman with rheumatoid arthritis who is found to have malignant pleural mesothelioma based on pathologic findings.