Histological type distribution and expression of nm23, VEGF, TOP2A and MUM-1 in peripheral T-cell and NK-cell lymphomas in Chinese: analysis of 313 cases.

Peripheral T cell and natural killer cell lymphomas (PT/NKCLs) are rare malignant tumors of lymphoid tissue. The incidence varies by geographical region and race. We reclassified 313 cases of PT/NKCLs based on the 4th edition of the World Health Organization (WHO) classification to demonstrate the distribution of each histologic type of PT/NKCLs in Chinese populations. In our series, extranodal NK/T-cell lymphoma (ENKT) was the most common (37.1%) type, followed by peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) (31.3%) and angioimmunoblastic T-cell lymphoma (AITL) (12.8%). Also, we investigated the expression level of nm23, VEGF, TOP2A, and MUM-1 in all 313 cases. The positive rate of nm23, VEGF, TOP2A, and MUM-1 expression was more than 50% in most histologic types. Among the five common types, the expression rate of nm23 (34.5%) and TOP2A (27.6%) in ENKT were the lowest (P<0.05). VEGF expression was also lowest in ENKT (26.7%), but it was much higher in PTCL-NOS (54.1%), AITL (70.0%), and ALCL-ALK- (56.5%) and ALCL-ALK+ (42.9%). The difference of VEGF expression between ENKT and PTCL-NOS and AITL was significant (P<0.05). Fourteen of 23 (60.9%) cases of ALCL-ALK- and 9 of 14 (64.3%) cases of ALCL-ALK+ were positive for MUM-1, which was much higher than in ENKT (19.8%), PTCL-NOS (26.5%) and AITL (35.0%) (P<0.05). Although the significance of their expression in PT/NKCLs is not clear, we suggested that they may be novel tumor markers for developing targeted therapy in the future.