無気肺経過観察中に診断された浸潤性粘液性腺癌の1例

Invasive Mucinous Adenocarcinoma Diagnosed During the Follow-up of Atelectasis：Report of a Case

はじめに　無気肺として経過観察中に緩徐拡大した肺野の陰影に対しCTガイド下生検を施行したところ，粘液性腺癌の可能性が否定できず，PET-CTで陰影の一部にFDG集積を認めたため手術を行い，無気肺に併存した浸潤性粘液性腺癌（invasive mucinous adeno carcinoma：IMA）と確定診断された症例を経験した．文献的考察を加え報告する．

A 72-year-old man underwent bronchoscopy for an abnormal shadow on chest imaging, but no definitive diagnosis was made. The lesion was followed for four years as atelectasis, during which time it gradually increased in size. A computed tomography （CT）-guided biopsy suggested mucinous adenocarcinoma；however, a definitive diagnosis remained elusive. Surgical resection was ultimately performed for both diagnostic and therapeutic purposes, and the patient was diagnosed with invasive mucinous adenocarcinoma. Invasive mucinous adenocarcinoma, characterized by abundant mucus components, may be difficult to diagnose through preoperative biopsy. Even when atelectasis is suspected, the possibility of invasive mucinous adenocarcinoma should be considered. Prompt re-evaluation is warranted when an enlarging shadow is observed. In some cases, surgical resection may be necessary as part of the diagnostic strategy.