Pulmonary small cell carcinoma associated with sarcoid reactions: Report of a case

A 45-year-old male was admitted to our hospital for investigation of a nodu lar shadow in segment 5 of the right lung on a chest computed tomogram. A r ight middle lobectomy with mediastinal lymph node dissection was performed under a diagnosis of lung cancer, and histologic examination confirmed smal l cell carcinoma. There were sarcoid reactions in the resected lymph nodes and the lung parenchyma, but no signs of systemic sarcoidosis were evident. Sarcoid reactions are rarely observed in the regional lymph nodes draining malignant tumors. Moreover, while they are most common in squamous cell ca rcinoma of the lung, they extremely rare in small cell carcinoma. To our kn owledge, this is only the third report of this unusual entity in the Englis h and Japanese literature.