PRIMARY MALIGNANT-LYMPHOMA OF THE INTESTINE - CLINICOPATHOLOGICAL ANDIMMUNOHISTOCHEMICAL STUDIES OF 39 CASES

Clinicopathologic and immunohistochemical features in 39 cases of prim ary intestinal non-Hodgkin's lymphoma (NHL) in Japanese patients were studied. Only resection materials in stage I-E and IIE-1 were included in this study because of the certainty that the intestine was the pri mary site of the lymphoma. The updated Kiel classification was used to classify NHL. Histologically, only two cases (5.1%) were follicular l ymphomas, and the others were diffuse lymphomas. Twenty-eight patients (71.8%) had high-grade NHL and 11 (28.2%) had low-grade NHL. Twenty ( 71.4%) of the 28 high-grade NHL were centroblastic lymphomas, and 14 ( 70.0%) of these 20 cases of centroblastic lymphoma were the polymorphi c variant. Ten (90.9%) of the 11 low-grade NHL were tow-grade mucosa-a ssociated lymphoid tissue (MALT) lymphomas. Macroscopically, 18 patien ts had polypoid masses, 17 ulcerative tumors and four had diffusely in filtrating NHL. Seven of the 10 low-grade MALT lymphomas were polypoid masses. Immunohistochemically, 35 lesions (89.7%) were of the B cell phenotype and three (7.7%) were of the T cell phenotype. In the remain ing case, the cell lineage could not be determined. No lesions were co nsidered to be of histiocytic origin. The 5 year survival rate for hig h-grade a cell lymphomas was poorer than for low-grade B cell lymphoma s, and the present study indicated that the histological grade of the intestinal B cell lymphomas was a prognostically significant factor.