폐에 발생한 낭성 고형성 종양과 유사한 상피 봉입체를 가지는 양성 전이성 평활근종 1례

Abstract

Benign metastasizing leiomyoma is a rare neoplasm, generally in women who have undergone hysterectomy for uterine leiomyoma. It is usually detected as incidental pulmonary lesion. A 40-year-old woman presented incidental mass in the lung. There was a solitary nodule in left lower lobe. She had a history of myomectomy for uterine leiomyoma 13 years before. Wedge resection was performed for diagnosis and treatment, and the mass consisted solid and cystic portion without hemorrhage or necrosis. On histologic examination, solid tumor portion showed sheets like pattern of spindle cells with cigar-like nuclei and occasional nuclear inclusions. No cellular atypia or mitosis was identified. Cystic portion showed abundant epithelial inclusions which were consisted of cuboidal or columnar epithelium. Spindle cells of the tumor were positive for SMA and epithelial cells of inclusion were positive for cytokeratin and TTF-1 on immunohistochemical staining. Benign metastasizing leiomyoma with many large epithelial inclusions may be similar to cystic and/or solid lesion of lung such as lymphangioleiomyomatosis, synovial sarcoma, pulmonary blastoma, pulmonary hamartoma or metastatic carcinoma with cystic change. Because benign metastasizing leiomymoa has better prognosis rather than other cystic and/or solid lesion of the lung, exact diagnosis should be required for appropriate treatment.