T，N，Mすべてで病期診断上のpitfallを有した肺癌の1例

A case of lung cancer with diagnostic pitfalls in T, N, and M staging

悪性腫瘍の病期診断は，治療方針決定の根幹をなすものであり，その中で画像診断は重要な役割を担っている。しかしながら，様々なpitfallにより時に実際の病期と異なる判断を招くことがある。今回我々は，T，N，M因子すべてにおいて病期診断上のpitfallを経験したまれな肺癌症例を経験したので報告する。

A woman in her 60s was referred to our hospital because of suspected lung cancer on CT. Biopsy confirmed adenocarcinoma. PET/CT showed a 1.9cm mass in the right S9 lung segment with FDG uptake（SUVmax＝5.2）and an enlarged right adrenal gland with FDG avidity（SUVmax＝7.1）, suggesting metastasis. The initial diagnosis was cT1bN0M1b, Stage ⅣA, and chemotherapy was planned. However, contrast-enhanced MRI indicated adrenal adenoma. The diagnosis was revised to cT1bN0M0, Stage ⅠA2, and surgery was performed. Postoperative pathology revealed pleural invasion and #7 lymph node metastasis, leading to a final diagnosis of pT2aN2aM0, pStage ⅢA. This case highlights pitfalls in staging, including pit-fall sign, skip metastasis, and FDG-avid adrenal adenoma.