Aims: To investigate the clinicopathological characteristics of 20 primary gastric T-cell lymphoma (GTCL) cases without human T-lymphotropic virus type I infection in Japan, a non-endemic area for coeliac disease.
Methods and results: Fifteen cases had no history of persistent diarrhoea or severe hypoproteinaemia. Histologically, 13 cases (65%) consisted of large cell lymphoma and seven (35%) were of medium-sized cells. Intraepithelial lymphoma cell invasion was found in three cases (15%). Two of 10 surgical cases (20%) showed intramucosal tumour cell spreading with enteropathy-like features. Helicobacter pylori CagA gene was detected in three of 10 cases (30%). The lymphoma cells of all 20 cases were positive for CD3 and/or TCRbetaF1 and negative for CD56. CD4- and CD8- lymphoma was found in 11 cases (55%), CD4+ lymphoma in seven (35%) and CD8+ lymphoma in two (10%). CD30+, CD5+ and CD25+ lymphomas were detected in nine (45%), 10 (50%) and 11 (55%) cases, respectively. Five-year survival of the 16 available cases was 54%. Early clinical stage and medium-sized cell lymphoma were significantly (P < 0.05) better prognostic factors.
Conclusions: Patients with GTCL exhibit distinct clinicopathological findings and prognoses from those with enteropathy-associated T-cell lymphomas. GTCL may be mainly derived from lamina propria and parafollicular T cells.