Autoimmune Rheumatic Disease (Polymyositis and Dermatomyositis) associated with Papillary Thyroid Carcinoma: Report of Two Cases and Review of the Literature

Autoimmune rheumatic diseases, such as polymyositis and dermatomyositis, have been demonstrated to carry a risk of the development of malignancy. Thyroid cancer is a rare occurrence in this setting; however, multiple cases have been reported. We present two cases of papillary thyroid carcinoma associated with dermatomyositis and polymyositis. The first patient is a 64-year-old female found to have papillary thyroid cancer after the diagnosis of polymyositis who underwent thyroid resection. The second patient is a 51-year-old male who was found to have synchronous papillary thyroid cancer and small cell carcinoma of the lung. He did not undergo thyroid resection due to widely metastatic lung cancer. We describe two cases of papillary thyroid cancer associated with autoimmune rheumatic disease. Though it is rare, thyroid cancer should remain in the differential diagnosis of a patient with new onset autoimmune rheumatic disease, as this may alter the eventual management of these patients.