両肺に多発する微小髄膜細胞様結節の1例

Multiple Minute Pulmonary Meningothelial-like Nodules；Report of a Case

はじめに　微小髄膜細胞様結節（MPMN）は，肺胞領域にみられる微小な病変であり，形態的に髄膜腫に類似している．われわれは，CT上で両肺に多発する微小な肺陰影を認め，胸腔鏡下肺生検により組織学的にMPMNと診断した1例を経験したので報告する．

A 57-year-old woman was referred to our hospital for investigation of multiple tiny nodules in the lung fields bilaterally on computed tomography （CT）. Video-assisted thoracoscopic lung biopsy was performed to diagnose the pulmonary lesions. Histological analysis showed nodular lesions with interstitial proliferation of uniform, round to oval cells with variable widening of the alveolar septa. Immunohistochemically, the cells were positive for EMA, CD56 and the progesterone receptor, but negative for chromogranin and synaptophysin. The diagnosis was “diffuse pulmonary meningotheliomatosis”, with multiple diffuse “minute pulmonary meningothelial-like nodules”. Diffuse pulmonary meningotheliomatosis should be kept in mind when we encounter small nodular shadows on a CT scan.