Lung metastases of a uterine tumor resembling ovarian sex-cord tumor: Report of a rare case.

Uterine tumor resembling an ovarian sex-cord tumor (UTROSCT) is a rare type of uterine neoplasm. We present an extremely rare case of lung metastases from a UTROSCT focusing on the cytologic features. A 69-year-old Japanese woman was admitted to our hospital for further examination and treatment for abnormal shadows in the right lung field. She had a history of total hysterectomy for UTROSCT. Moreover, she underwent wedge resection of the right middle lobe for lung metastasis of UTROSCT in 2011. Enhanced chest computed tomography scan revealed a solid nodule 8 mm in diameter in the right upper lobe and a well-demarcated 33-mm mass or nodule in the lower lobe. Under the diagnosis of metastatic tumors from UTROSCT, she underwent wedge resection of the right upper lobe and segmentectomy of the right S8. Cytologically, the stump smear from the resected tumors revealed round to short spindle-shaped neoplastic small cells arranged in sheets with poor cohesion and no cluster formation. The nuclei were irregular in shape, and the chromatin was finely granular, uniform, and increased. Mitotic figures were not observed. Necrosis was absent in the background. Histologically, the final diagnosis was UTROSCT group II. This is an unusual case of metastatic UTROSCT to the lung in which the cytologic features are described.