生検で診断しえたReactive Lymphoreticular Hyperplasiaの1例

Reactive Lymphoreticular Hyperplasia, a Case Accurately Diagnosed by Biopsy

　胃 Reactive Lymphoreticular Hyperplasia（以下胃R. L. H.）は1928年Konjetznyが慢性胃炎の特殊型として記載しており，臨床的にはX線・内視鏡で早期胃癌と類似した像を示すためその鑑別が求められ，組織学的には悪性リンパ腫への移行に興味が注がれている．その本態については疑問な点も多いが，炎症性および反応性増殖と腫瘍性との問題をめぐり議論が繰返されている．われわれはX線・内視鏡でⅡcを疑い，生検を行なって術前に診断をつけ得た胃R. L. H.を経験し，その組織学的検索で興味ある所見を得たので報告する．

　A 63-year-old man was admitted to Shinshu University Hospital because of melena and hematemesis persisting on and off for 6 years.

　He was slightly anemic without any other clinical changes. The gastric juice was hypoaciditic.

　By x-ray examination of the stomach, a Ⅱc-like lesion was widely spread from the infracardiac portion to the antrum on both anterior and posterior walls. Gastrofiberscopically, the depressed area showed many varied appearances such as converging mucosal folds, erosions, minute ulcers, bleedings and white patches.

　These findings are considered but not conclusively diagnosed as Reactive Lymphoreticular Hyperplasia (RLH), and Ⅱc early carcinoma could not be ruled out. Biopsy revealed marked diffuse proliferation of lymphocytes invading the muscularis mucosae and we entertained a strong suspicion of the diffuse flat form of RLH. The atypia of these proliferating lymphocytes was not so evident and lymphosarcoma was excluded. On the gross appearance, the faintly depressed hyperemic lesion spread mostly all over the resected stomach mucosa except the prepyloric area. The boundary of the lesion was difficult to follow unlike that of Ⅱc carcinoma and many erosions and minute ulcers were scattered about.

　Histologically, remarkable proliferation of lymphocytes was observed on the mucosa and submucosa and follicular structures were locally seen. The lymphnodes showed diffuse hyperplasia of the lymphocytes in the pulp and the dilated sinuses were filled with small lymphocytes.

　The behavior of RLH has been discussed and the diffuse flat form of it is considered as kataplastic hyperplasia of the lymphoid tissue in the gastric mucosa.