Thymic carcinomas are rare neoplasms representing less than 1% of all thymic malignancies arising from thymic epithelium. Lymphoepithelioma-like thymic carcinoma is a high grade neoplasm with aggressive features and frequent metastasis. Association of lymphoepithelioma-like thymic carcinomas with Epstein-Barr virus was observed in several previously reported case reports. Paraneoplastic syndromes have been reported with lymphoepithelioma-like thymic carcinoma. We report a case of rare association of paraneoplastic syndrome of polymyositis with lymphoepithelioma-like thymic carcinoma. The case highlights generalized increase in fluoro-deoxy-glucose uptake in the skeletal muscles indicating biopsy proven polymyositis-a paraneoplastic syndrome.