[A case of pulmonary leiomyosarcoma followed up for five years]

A 70-year-old woman with leiomyosarcoma, followed up for 5 years as tuberculoma, is described. The tumor, in the left lower lobe, had enlarged from 1.5 x 1.5 cm to 3.4 x 3.4 cm in 5 years, and doubling time was calculated to be 540 days. Another tumor (1.8 x 1.8 cm) was also recognized in the right lower lobe at the later time. Since not only a benign tumor but metastatic disease was suspected, thoracotomy was performed, and the intraoperative pathologic diagnosis was leiomyosarcoma. However, only partial lung resection was performed because of the low growth rate of the tumor, the patient's advanced age, limited lymphatic metastasis and favorable prognosis with only partial resection. DNA analysis of the tumor based on flow cytometry showed a diploid pattern, and this was thought to account for the long doubling time of the tumor. The postoperative course was satisfactory without any signs of recurrence at the operation site.