[Characteristics of B-cell lymphoma in Japan]

Consecutive 431 patients with B-cell lymphoma seen in Aichi Cancer Center Hospital from 1964 to 1988 were analysed. Median age was 56 yr (range 8-86). There were 76 patients (17.6%) with follicular lymphoma and 355 with diffuse lymphoma. Among the 30 patients with follicular lymphoma, 10 (33%) were found to have a bcl-2 rearrangement. The incidence was lower than those reported in the United States. This might contribute to the lower incidence of follicular lymphoma cases in Japan. There were 168 patients (39.0%) with nodal lymphoma and 263 with extranodal lymphoma. Eight-four cases arose from the stomach, 84 from Waldeyer's ring, 21 small intestine and 13 thyroid. The distributions of extranodal B-cell lymphoma differed from those of T-cell lymphoma. Patients with gastric lymphomas in stage I were treated with resection alone. In the same manner, patients with Waldeyer's ring lymphoma in stage I were treated with radiotherapy alone. More than 90% of these patients were expected to survive without relapse. On the other hand, only 55% of patients with nodal lymphoma in stage I were expected to survive for more than 10 years. These findings suggest the site of localized lymphoma is an important determinant of outcome of clinical behavior.