Use of an expanded immunohistochemical panel to distinguish cutaneous Hodgkin lymphoma from histopathologic imitators.

Jan 2012

Cho RJ, McCalmont TH, Ai WZ, Fox LP, Treseler P, Pincus LB.

Source

Department of Dermatology, University of California, San Francisco, CA, USA Department of Pathology, University of California, San Francisco, CA, USA Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, CA, USA.

Abstract

In lymph nodes, classical Hodgkin lymphoma can typically be distinguished from non-Hodgkin lymphoma (NHL) by the presence of Hodgkin and Reed-Sternberg cells that co-express CD30 and CD15. However, anaplastic large cell lymphoma(ALCL) and diffuse large B-cell lymphoma (DLBCL) can show identical features, and some cases of classical Hodgkinlymphoma lack CD15 expression, rendering them difficult to differentiate from CD30-positive NHL. The differential diagnosis of cutaneous Hodgkin lymphoma similarly includes ALCL and DLBCL, and, additionally, tumors of mycosis fungoides. Recent studies have shown that classical Hodgkin lymphoma is of B-cell origin in virtually all cases, and shows at least focal weak expression of the B-cell marker PAX5 and often focal weak expression and no expression of the B-cell markers Oct-2 and BOB.1, respectively. All three of these markers are almost invariably absent in T-cell lymphomas and are strongly expressed in B-cell lymphomas. We report a 40-year-old man with classical Hodgkin lymphoma who developed cutaneousnodules. A biopsy from one revealed Hodgkin/Reed-Sternberg cells with a similar immunophenotype to the diagnostic lymph node biopsy, namely CD30+/CD15+, diffusely but weakly PAX5+, focally weakly Oct-2+ and lacking BOB.1 expression, thereby confirming a diagnosis of cutaneous Hodgkin lymphoma. To our knowledge, this is the first report of the expression pattern of the combination of PAX5, Oct-2 and BOB.1 in the context of cutaneous involvement by Hodgkin lymphoma. Cho RJ, McCalmont TH, Ai WZ, Fox LP, Treseler P, Pincus LB. Case report demonstrating use of an expanded immunohistochemical panel to distinguish cutaneous Hodgkin lymphoma from histopathologic imitators.

PubMed