Hodgkin lymphoma with unusual intrasinusoidal pattern of infiltration

In spite of recent great advances in our understanding of both Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL), occasionally there are CD30-positive large cell hematopoietic neoplasms, in which the morphologic and phenotypic features overlap to such an extent that they cannot easily be classified. We report a histologically unusual case of HL that mimicked ALCL, but had phenotypical characteristics of HL. The neoplastic cells resembling Reed-Sternberg cells or Hodgkin cells were mainly situated within sinusoidal spaces, which are characteristically seen in ALCL. However, they showed unequivocal expression of both CD30 and CD15, and no aberrant antigen expression to suggest ALCL (BSAP+, EMA-, LCA-, CD43-, CD2-, CD3-, CD4-, CD45RO-, ALK-, granzymeB-), with negative TCR gene rearrangement and no expression of EBV. HL with intrasinusoidal pattern has rarely been described, but we suggest that, although cases of HL with such a striking sinusoidal pattern are rare, nevertheless do exist. Since the identification of sinusoidal infiltration by CD30-positive neoplastic cells may lead to a mistaken view of ALCL, wide panel of antibodies should be used to confirm the diagnosis.