Cutaneous intravascular natural killer/T cell lymphoma with peculiar immunophenotype

Intravascular lymphoma ( IVL ) is a rare entity. Most cases are a variant of extranodal diffuse large B cell lymphoma, and fewer than 10% of the published cases are of T cell origin. Only intravascular B cell lymphoma is recognized as a distinct entity in the most recent World Health Organization ( WHO ) classification of lymphoproliferative disorders. We describe a case of cutaneous natural killer ( NK )/T IVL , with a cytotoxic immunophenotype and Epstein–Barr virus ( EBV ) positivity. However, our case was immunohistochemically negative not only for T cell receptor ( TCR )‐βF1 and TCR ‐γ ( TCR ‐silent), but also for CD 56, making it the first triple‐negative NK /T IVL case to be described. We urge recognition of this NK /T cell lineage intravascular lymphoma due to its particular immunophenotypical profile and its unvarying relationship with EBV . Its occurrence should not be considered a coincidence, but rather a key aspect of the pathogenic background of this haematological neoplasm.