NASAL T NK CELL LYMPHOMA - A CLINICO PATHOLOGICAL-STUDY OF 30 WEST CHINESE PATIENTS WITH SPECIAL REFERENCE TO PROLIFERATION AND APOPTOSIS/

Midfacial T-cell lymphomas are more prevalent in Asia than in Europe o r North America. Clinically, these lymphomas are noted as one major di fferential diagnosis in the malignant midline granuloma syndrome. Duri ng the past years, the group of nasal T/NK cell lymphomas has been rec ognized that is frequently associated with EBV-infection. The aim of t he current publication was to describe the clinical presentation and c ourse of 30 patients attending the West China University of Medical Sc iences, Chengdu, P. R. China, between 1991 and 1994. Clinical records were assessed and the patients were followed for 6 to 29 (mean 12.4) m onths. Several microscopic features thought to be associated with this entity were carefully evaluated together with immunohistochemical dat a. The proliferation of the tumour cells was assessed by determining t he mitotic index and the ratio of MIB-1 labelled cells. In addition, t he incidence of apoptotic cells was investigated by means of the in-si tu end labelling (ISEL) technique.Our data confirm the expression of T -cell markers by T/NK cell lymphomas as determined by the immunohistoc hemistry. The apoptotic index was found to correlate with the ratio of MIB-1 labelled cells. Expression of the bcl-2 oncoprotein was not ass ociated with increased or diminished proliferation or cell death, resp ectively. Eight of the thirty patients succumbed to their disease duri ng the follow-up period. Kaplan-Meier cumulative survivals and log-ran k tests revealed a significant impact of MIB-1 labelling on mean survi val times.