空洞を呈した末梢型肺小細胞癌の1例

金沢大学医薬保健研究域医学系An 81-year-old man presented with productive cough. He was adrnitted because of an abnormal shadow in the left upper lung field on chest X-ray. Chest CT scan showed a multilocular mass shadow in left S1+2 with cavity forrnation and small shadows suggestive of metastases around the primary mass. One of the latter shadows also contained a cavity. Sputum cytology and pleural effusion cytology showed class V , small cell carcinoma. The transbronchial lung biopsy specimen showed many small cells with dense nuclei and scanty cytoplasm, so a diagnosis of small cell carcinoma was made. Cavity formation in primary carcinoma of the lung is fairly common, with the reported incidence ranging from 2 to 16 percent. However most such cases are squamous cell carcinoma or adenocarcinoma, not small cell carcinoma. Sm.all cell carcinoma showing a multilocular mass shadow with cavities in the primary and a metastatic lesion, as seen in the present case, is rare. 症例は81歳男性で,湿性咳嗽にて受診し,胸部レントゲン写真上左上肺野の異常陰影を指摘され入院となった.胸部CT上左S1+2に多房性の腫瘤を認めた.内部に空洞を伴い周囲に複数の小転移巣を伴っていた.小転移巣の1つにも空洞がみられた.喀痰細胞診,胸水細胞診にてclassV小細胞癌の所見が得られた.軽気管支肺生検での病理組織所見では,小型で濃染性の核を有する細胞が多く,細胞質は狭小であり,小細胞癌と診断された.原発性肺癌での空洞形成率は,2〜16%とされていて稀ではないが,ほとんどは扁平上皮癌,腺癌であり,小細胞癌という報告はほとんどない.本症例のように,多房性の腫瘍で,原発巣及び転移巣に空洞形成を呈した肺小細胞癌は,貴重な症例と考えられた