[A clinical and pathological study of 24 cases of primary non-Hodgkin's lymphoma of the orbit].

Primary non-Hodgkin's lymphoma of the orbit predominantly consists of the small lymphocytic, the lympho-plasmacytic, and the schistocytic types. Because of fair cellular differentiation, the tumor shows low or medium atypia as if benign. Hence, differential diagnosis from inflammation pseudotumor or lymphocytic hyperplasia is important. Follow-up of 18 of the present 24 cases showed that the tumor usually began insidiously and was long confined to the orbit. 44% (8/18) of the patients had relapses and 22% (4/18) died of systemic dissemination 2-6 years after confirmed diagnosis, a finding in agreement with Kinyh et al, who reported a 5 year survival rate of 75% and a 8 year survival rate of 50%. The prognosis was better than that of intranodal or extranodal non-Hodgkin's lymphoma in other locations.