Extranodal nasal-type natural killer/T-cell lymphoma of the skin: a clinicopathologic study of 16 cases in China.

Extranodal nasal-type natural killer/T-cell lymphoma presenting in skin, either primary or secondary, is relatively rare in China, accounting for about 4.1% of tumors. The clinicopathologic features of the neoplasm are still poorly understood. Sixteen Chinese cases of cutaneous natural killer/T-cell lymphomas were investigated retrospectively by pathology, immunophenotype, genotype, Epstein-Barr virus status, and survival analysis. The mean age of the patients was 36.3 years; 81% of the patients presented with multiple cutaneous lesions. Angiocentricity and epidermotropism were observed in 43.7% and 25%, respectively; the average number of mitoses was 12 per 10 high-power fields. The neoplastic cells of all 16 cases were positive for CD3varepsilon/CD45RO and granzyme B and negative for CD4, CD5, CD8, and CD20; 87.5% of the tumors expressed CD56. Signals for EBER were detected in 81.3% of cases. No clonal TCRgamma/TCRbeta gene rearrangement was demonstrated. Thirteen of 15 patients received chemotherapy; a partial response was achieved in 10 patients; 10 (66.7%) of 15 patients died of the disease, and the average survival time was 6.6 months. In conclusion, both primary and secondary cutaneous natural killer/T-cell lymphomas are highly aggressive. The outcome is closely related to the number and distribution of the lesions as well as the stage. In patients with generalized skin lesions and extracutaneous involvement, the prognosis usually is poor.