Subcutaneous metastases of sarcomatoid mesothelioma with its differential diagnosis on fine needle aspiration--a case report.

Metastasis of mesothelioma of the pleura, to the skin and subcutis is an extremely rare occurrence. A 25 year old woman, who had undergone chemotherapy, partial excision of tumor followed by radiotherapy of sarcomatoid mesothelioma of the pleura, presented three months later with painless widespread subcutaneous nodules. FNAC of these nodules reveled pleomorphic malignant spindle shaped cell with epithelioid morphology. The subcutis is a particularly rare site of metastatic sarcomatoid mesothelioma. It is essential to differentiate neoplasm metastatic to the skin and subcutis from primary and benign lesions of the same region. FNAC is accurate and efficient, in conjugation with clinical history, and it also prevents surgical biopsy in the diagnosis of metastatic subcutaneous lesion. To our knowledge, this is the first case, reported till date, in which the sarcomatoid mesothelioma metastasized to the subcutaneous tissue and was diagnosed by fine needle aspiration cytology (FNAC).