IPSIDとの鑑別に苦慮した十二指腸球後部の髄外性形質細胞腫の1例

Extramedullary Plasmacytoma of the Duodenum, Report of a Casc

要旨　患者は73歳，女性．20年前に特発性門脈圧亢進症で脾臓摘出術ならびに食道離断術が施行されている．1987年8月，食道静脈瘤の経過観察のため上部消化管内視鏡検査を施行した際，十二指腸球後部にひだの腫大と粘膜面の顆粒状変化を認めた．同時に行った生検で（immunoproliferative small intestinal disease（(以下IPSID)の疑いが持たれ，小腸造影，注腸造影が施行されたが，上記のひだの腫大は十二指腸球後部に限局していることが確認された．入院後の諸検査と再生検から，IPSIDではなく，形質細胞腫と診断された．全身の系統的な検索で偶然，盲腸に癌が発見されたため，回盲部切除術がなされ，その際の腹腔内の検索でも，形質細胞腫は十二指腸に限局していることが確認された．合併疾患との兼ね合いから現在無治療で経過を観察中であるが，1年4か月を経ても病変に変化は認められない．

　A 73-year-old Japanese woman who had received the surgical operation of esophageal transection and splenectomy for idiopathic portal hypertension took gastrointestinal endoscopic examination in order to evaluate esophageal varices. At this time a swelling of the fold with granular mucosa in the duodenum was fount by chance. In the biopsy specimen, a large number of plasma cells was seen in the mucosal lamina propria, and most of the plasma cells were stained with immunoperoxidase labelled anti-IgA and anti-lambda antisera. At first this case was considered as one of the immunoproliferative small intestinal diseases, but alphaheavy chain protein was not found in either her serum or duodenal juice. Therefore, we diagnosed it as extramedullary plasmacytoma. Systemic examination of the gastrointestinal tract as well as of the bone revealed that there was no massive plasma cell infiltration in the gastrointestinal tract except for that in the duodenum, but a colon cancer was found in the cecum. Ileocecal resection was carried out and there was no evidence of abdominal lymph node swelling, but extirpation of duodenal plasmacytoma was not. performed because of her rather advanced age and fear of complications. At present this patient is not being given anti-tumor therapy, but she is being followed up, and the duodenal tumor is not increasing in size.