炭酸ランタンによる胃粘膜病変の2例

Gastric Mucosal Lesions Caused by Lanthanum Carbonate, Report of two Cases

要旨●炭酸ランタンによる特徴的な胃粘膜病変の2例を経験した．患者はいずれも末期慢性腎臓病で血液透析を受けている70歳代の男性で，炭酸ランタンを服用中であった．上部消化管内視鏡検査では，胃に白色微細顆粒の多発を認めた．同部位からの生検組織診断では粘膜固有層間質に組織球の集簇を認めた．組織球の胞体内には赤褐色調の種々の形態を呈する物質を認めた．近年，炭酸ランタン服用による組織球集簇を特徴とする胃粘膜病変の報告が散見されている．この病変の発症機序と長期的な生体への影響ははっきりしておらず今後の注意深い経過観察，症例の蓄積，検討が必要と思われた．

　We experienced two cases of characteristic gastric mucosal lesions caused by lanthanum carbonate. The patients had been undergoing hemodialysis for end-stage chronic kidney disease and were receiving oral lanthanum carbonate. On endoscopy, a large number of white, fine granules were observed in the gastric mucosa. Biopsy specimens showed accumulation of histiocytes in the lamina propria. In addition, a brownish material of various forms（granular, needle shape, mesh-like）was observed in the cytoplasm of histiocytes. Recently, several studies have reported gastric mucosal lesions characterized by histiocytic accumulation in patients receiving lanthanum carbonate. The underlying mechanism of such lesions is unknown, and their long-term effects on the body are also unclear. Thus, careful observation and accumulation of such cases is warranted.