[Pathology and prognosis of 378 cases of primary intestinal malignant lymphoma (IML)]

Pathology and prognosis of 378 cases of IML collected from 28 colleges or hospitals, are reported. The ratio of male and female was 2:1. Ages ranged from 3 to 86 years with a peak age of 21-50. Main symptoms were abdominal pain, mass, intestinal obstruction, diarrhea and intestinal bleeding. The tumor occurred, in order of incidence, in small intestine (42%), ileocecal region (30%), colon (13%), cecum (8%), rectum (3%), duodenum (2%) and anorectum (1%). Multifoci were found in 43 cases (11%). Grossly, the tumor was divided into three types: exophytic, ulcerative and diffuse infiltrative. In histology, follicular type comprised 4% (16 cases) and diffuse type, 96% (362 cases). In the latter, the majority was cleaved, non-cleaved or mixed cell type originating from the follicular center cells. There were a few T cell lymphomas and true histiocytic types but no Hodgkin's lymphoma. Statistically, the prognosis was significantly related to the depth of invasion, gross type, tumor size and stage. By histology, lympho-plasmacytoid type and small lymphocytic type had better prognosis compared with the other diffuse types. In this series, 83 patients were treated by surgery (including operation plus chemotherapy). The survival rate of less than 1 year was 51%, nearly equal to the survival rate of more than 1 year (49%). 10 patients have survived more than 5 years and 6, more than 10 years, 2 of them, more than 18 years. It indicates that the operation plays an important role for prolonging survival. Early detection, early diagnosis and early operation are necessary.