Published case study – the first triple negative case of Cutaneous NK/T-cell Intravascular Lymphoma with cytotoxic immunophenotype and EBV positivity

On 2^nd August 2017, in Histopathology, Victoria Alegría-Landa from Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain, et al. published a case report of a Caucasian male, 81 years of age, with Cutaneous Natural Killer (NK)/T-cell Intravascular Lymphoma (IVL).

Key Highlights:

• History of colorectal cancer removed surgically five years before, severe chronic obstructive pulmonary disease, and frequent hospital visits to control infectious exacerbations and secondary respiratory failure
• On a hospital visit, purpuric asymptomatic linear plaques were observed on the patient’s trunk; particularly abdomen and flanks
• No palpable lymphadenopathy or hepatosplenomegaly observed
• Biopsy from skin or right abdomen indicated lymphocytic infiltrate filling and expanding the lumina of dermal blood vessels; no surrounding inflammation
• The majority of lymphocytes were medium sized, some large cells also present; irregular nuclear contour, hyperchromatism, and some mitotic figures
• Lymphocytes were positive for CD3, granzyme B, perforin, and CD30, as well as negative for CD20, CD4, CD8, TCR-βF1, TCR-γ, and CD56 (triple negative)
• In situ hybridization identified Epstein-Barr Virus (EBV) encoded RNA in the majority of the nuclei of the intravascular lymphocytes
• PCR based studies identified clonal rearrangements of TCR-γ and TCR-β
• Total-body CT scan found no internal involvement
• Due to rapid deterioration of the patient, supportive treatment was given and he passed away after a few days

IVL is rare and the majority of cases are a type of extranodal Diffuse Large B-Cell Lymphoma (DLBCL). Less than 10% of reported cases are of T-cell origin. This current case of cutaneous NK/T-cell IVL with cytotoxic immunophenotype and EBV positivity is the first triple negative (TCR-βF1, TCR-γ, and CD56) case to be described. This entity has not yet been classified by the World Health Organization and the authors urge that is should be considered as a distinct subtype in future classifications.

Abstract:

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 WHO classification of lymphoproliferative disorders. We describe a case of cutaneous NK/T IVL, with a cytotoxic immunophenotype and EBV positivity. However, our case was immunohistochemically negative not only for TCR-βF1 and TCR-γ (TCR-silent), but also for CD56, making it the first triple-negative NK/T IVL case to be described. We urge the recognition of this NK/T-cell lineage intravascular lymphoma due to its particular immunophenotypic 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.