Classical Hodgkin Lymphoma With Aberrant CD8 Expression: A Clinicopathologic Study of Five Cases.

Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (CHL) are of B-cell origin. In a small number of CHL cases, the tumor cells can express T-cell antigens. CD8 expression in this setting is extremely rare. We identified 5 cases of CHL with aberrant CD8 expression from our database. The patients included 3 men and 2 women with a median age of 33 years (range = 20-59 years). All the patients initially presented with lymphadenopathy and variable number of RS cells. Two cases were classified as mixed cellularity type that showed prominent vascular proliferation mimicking peripheral T-cell lymphoma. Two cases represented nodular sclerosis type. The tumor cells in all cases were positive for CD8 and negative for CD2, CD3, CD4, and CD7 and carried germline T-cell receptor genes. Molecular studies revealed T-cell receptor genes to be in germline configuration in 4 cases with available information. Given the morphologic overlap with peripheral T-cell lymphoma and the rarity of this type of CHL, identifying more cases will help our better understanding of this entity.