OBJECTIVETo study the clinicopathologic features and disease outcome of intravascular natural killer-cell lymphoma (IVNKL).

METHODSThe histologic features, immunohistochemical findings and results of in-situ hybridization for Epstein-Barr virus-encoded RNA (EBER) were analyzed in 2 novel cases of IVNKL. Seven cases of IVNKL previously reported in the literature were reviewed.

RESULTSThe patients were a 68-year-old woman and a 22-year-old man. They both presented with erythematous patches and nodules on their trunk and extremities. Skin biopsies confirmed the diagnosis of IVNKL. The tumor cells were positive for CD3, CD56, granzyme B and EBER. Both patients died 2 months after the diagnosis. Amongst the 9 reported cases, including those from the literature, the male was 4 cases, the female was 5 cases. The mean age of the patients was 45.7 years and the median age was 47 years. Skin lesions represented the commonest clinical manifestations. Multiple organ involvement was found in 7 cases and central nervous system was involved in 3 cases. Six patients died during 2 to 17 months of follow-up. The median survival was 9 months and the one-year survival rate was (35.6±18.6)%. The clinical outcome of the patients with multiple organ involvement was worse than that with skin manifestations only. The difference however was not statistically significant (P=0.083).

CONCLUSIONSIVNKL is a rare disease. Diagnosis should be made according to typical histologic findings, immunophenotype and EBER in-situ hybridization results. The overall prognosis of IVNKL is poor. Early diagnosis and treatment before multiorgan involvement may be helpful in improving the clinical outcome.