高悪性度病変を含む若年者肺粘表皮癌の1例

Resected Pulmonary Mucoepidermoid Carcinoma Containing High-grade Lesions in a Young Adult：Report of a Case

はじめに　肺粘表皮癌は全肺癌の0.1～0.2％と発生頻度が低く1），大部分が低悪性度病変とされる2）腫瘍である．われわれは高悪性度病変を含む若年者肺粘表皮癌の1切除例を経験したので報告する．

A 20-year-old female underwent a health checkup that revealed an abnormal shadow in the left upper lung field on a chest radiograph. A further examination with chest computed tomography （CT） showed a 25 mm solid tumor in the center of B1＋2 in the left upper lobe. A biopsy of the tumor obstructing the left B1＋2 was performed during bronchoscopy, and a pathological study diagnosed it as mucoepidermoid carcinoma of the lung. The patient underwent left upper lobectomy and lymph node dissection （ND2a-1）. The pathological diagnosis was pT1cN0M0, indicating a predominance of high-grade lesions due to the presence of more solid components, including squamous and intermediate cells, than the mucous components. The nucleoli of these cells were distinct and were accompanied by cellular atypia. While most mucoepidermoid carcinomas of the lung are low-grade lesions, this case contained high-grade lesions, requiring careful postoperative follow-up.