OBJECTIVETo provide an ideal animal model for exploring pathogenesis and experimental treatment of primary colonic lymphoma.

METHODSPrimary colonic and liver metastatic lymphoma tissues were obtained from the surgical specimens,and transplanted into colonic mucosa of nude mice respectively. The tumorigenesis, invasion, metastasis and morphology of the transplanted tumor were observed. Karyotype was analyzed and DNA content was measured.

RESULTSAccording to the new WHO classification of malignant lymphoma, two high metastatic models (HCBL-0303 from primary lymphoma and HCBL-0304 from live metastatic lesion) of human primary colonic non-Hodgkin's B cell lymphoma in nude mice were established successfully by orthotopic transplantation. Pathological examination showed poorly differentiated non-Hodgkin's B cell lymphoma of the transplanted tumors, and immunohistochemical staining showed positive expressions of CD19, CD20 and CD22, and negative expressions of CD3 and CD7. The number of chromosome ranged from 55 to 59, and DNA index (DI) was 1.59 - 1.71 (i.e. heteroploid). In HCBL-0303,liver metastasis rate was 63.7% and lymph node metastasis rate was 56.4%. However, in HCBL-0304, both metastasis rates of liver and lymph node were 100%. The transplanted tumors grew autonomously and invasively in nude mice, and further developed hematogenous, lymphatic metastasis and intraperitoneal seeding.

CONCLUSIONSHCBL-0303 and HCBL-0304 are the first established high metastatic models of primary colonic lymphoma, and can be applied to the research on pathogenesis, invasion,metastasis and experimental therapy of human primary colonic lymphoma.