胃形質細胞腫の1例

Gastric Plasmacytoma, Report of a Case

要旨　患者は71歳の男性．主訴は嚥下時の心窩部痛．検査成績では特記すべきことなし．胃X線および内視鏡検査において，噴門直上にBorrmann2型胃癌様の病変と穹窿部に中心陥凹を伴った粘膜下腫瘍様の隆起性病変を認めた．前者からの生検で胃形質細胞腫を疑い，手術施行した（胃全摘，膵脾合併切除，R₂リンパ節郭清）．病理検査では噴門直上のBorrmann2型様病変は，κ鎖をモノクローナルに産生する形質細胞腫であり，穹窿部の病変は迷入膵であった．術後，cyclophosphamide 50mg/日と，predonine 5mg/日による化学療法を施行し，再発の徴候はない．本邦例28例について文献的に考察した．

　Extramedullary plasmacytoma of the stomach is an extremely rare disease. This is a report of the gastric plasmacytoma producing κ-chain immunoglobulin and a review of the plasmacytoma reported in Japanese literature.

　A 71 year-old man was admitted to our hospital with his chief complaint being epigastralgia at feeding. Laboratory investigation showed no abnormalities. X-ray and endoscopic examinations of the upper gastrointestinal tract demonstrated an ulcerative lesion like Borrmann 2 type gastric cancer at the upper part of the cardia and a smooth elevated tumor, which was covered with normal gastric mucosa accompanied by a central dimple at the fornix (Fig. 1, 2).

　Histologic study of the biopsy specimens taken from the ulcerative lesion revealed clusters of plasma cells.

　On November 7, 1984, a total gastrectomy with splenectomy, distal pancreatectomy and lymphadenectomy (R₂) was performed. Gross appearance of the resected stomach showed an ulcerative lesion measuring 27×22 mm and a protruded tumor distally (Fig. 3).

　Histologic examination revealed the ulcerative lesion to be invaded by plasma cells like neoplastic cells producing κ-chain immunoglobulin monoclonally (Fig. 4, 5). The smooth protruded tumor was Heinrich Ⅲ type of aberrant pancreas. The patient has been treated with cyclophosphamide (50 mg/day) and prednisolone (5 mg/day) and at present, has no evidences of recurrence.