Gastrointestinal malignant lymphoma: a pathologic study of 37 cases in a single Japanese institution.

The author reviewed pathologic features of 37 cases of malignant lymphoma in the gastrointestinal organs in the last 10 years in our pathology laboratory. The current WHO classification was adopted. The 37 cases consisted of 20 males and 17 female, and the age ranged from 46 to 89 years with a median of 69 years. Of the 37 cases, 25 cases (68%) were gastric lymphomas, 6 cases (16%) were small intestinal lymphomas, and 6 cases (16%) were colon lymphomas. Of the 37 cases, 35 cases (95%) were B-cell neoplasms and 2 cases (5%) were T-cell neoplasms. In the 25 gastric lymphomas (male:female=14:11, age range 46-84 years, median 70 years) 11 cases were diffuse large B-cell lymphomas, and 14 cases were extranodal marginal zone B-cell lymphomas (MALT lymphomas). The clinical endoscopic diagnosis was gastritis in 3, gastric ulcer in 3, gastric carcinoma in 7, carcinoid in 1, submucosal tumor in 1, malignant lymphoma in 2, and suspected MALT lymphoma in 8. In the 6 small intestinal lymphomas (male:female=2:4, age range 49-89 years, median 70 years), all cases were located in the ileum. Of the 6 cases, 4 were diffuse large B-cell lymphoma and 2 were peripheral T-cell lymphoma. One case showed multiple lymphomas, and one case was associated with rectal adenocarcinoma and one case with gastric MALT lymphoma. The clinical diagnosis was adenocarcinoma in 2, suspected lymphoma in 2, and ileal tumor in 2. In the 6 colon lymphomas (male:female=4:2, age range 69-86 years, median 74 years), 5 cases were diffuse large B-cell lymphomas and one case was follicular lymphoma. Clinical endoscopic diagnosis was GIST in 1, colon carcinoma in 4, and colon polyp in 1. Cases of Hodgkin's disease, mantle cell lymphoma, Burkitt lymphoma were not recognized in the present series. In summary, the author reported pathologic features of 37 cases of gastrointestinal malignant lymphoma in our laboratory in the last 10 years.