[A case of pulmonary tumorlet with tuberculoma misdiagnosed as small cell lung carcinoma by transbronchial lung biopsy].

A 59-year-old woman was picked up by chest X-ray findings. Her CT scan film showed a tumor shadow in the upper lobe of the left lung, and by transbronchial lung biopsy, she was diagnosed as a small cell lung carcinoma. Lobectomy was performed, but the lesion was diagnosed as tuberculoma by frozen section. Furthermore, on postoperative histological examination, a minute lesion of tumorlet, which was histologically identical to that preoperatively detected by transbronchial lung biopsy was found in the adjacent tissues of the tuberculoma. Pulmonary tumorlet is clinically a rare lesion, but the diagnosis and treatment for small-sized tumor or tumor-like lesion may be carefully done, taking into account the existence or co-existence of tumorlet lesion.