同一病巣内に混在した肺腺癌とサルコイドーシスの肉芽腫病変

Coexistence of Lung Adenocarcinoma and Non-caseous Epithelioid Granuloma Possibly due to Systemic Sarcoidosis in the Same Lesion

肺癌と肉芽腫が同一病巣内に共存することはまれである．われわれは，サルコイドーシス（systemic sarcoidosis：SS）と考えられる類上皮細胞性肉芽腫が肺癌と同一病巣内に存在する，めずらしい症例を経験した．本邦における同様の報告例の解析と，癌に伴うサルコイド様反応（sarcoid reaction：SR）との組織学的鑑別に関する考察を加えて報告する．

A lung cancer coexists with non-caseous epithelioid granulomas （NEG） in the same lesion is uncommon. A 62-year-old female was referred to our hospital for examination of a right lung S3 nodule which was recently increasing in its size. Positron emission tomography-computed tomography （PET-CT） examination revealed positive signals at the S3 nodule as well as mediastinal lymph nodes, apex of heart and right pleura. Pathological examination revealed the S3 nodule coexisting with both adenocarcinoma and NEG. The differential diagnosis between the systemic sarcoidosis and sarcoid reaction is usually important in such a case. Since the pleura and mediastinal lymph nodes contained many NEGs, the adenocarcinoma arising based on the systemic sarcoidosis was possibly suggested in the present case.