Use of an expanded immunohistochemical panel to distinguish cutaneous Hodgkin lymphoma from histopathologic imitators.
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 Hodgkin lymphoma 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 cutaneous nodules. 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.
Department of Dermatology, University of California-San Francisco, 1701 Divisadero St., San Francisco, CA 94115, USA.
Raymond J
RJ
Cho
Timothy H
TH
McCalmont
Weiyun Z
WZ
Ai
Lindy P
LP
Fox
Patrick
P
Treseler
Laura B
LB
Pincus
D000328:Adult; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D003937:Diagnosis, Differential; D006689:Hodgkin Disease / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D050813:Octamer Transcription Factor-2 / Q000378:metabolism*; D051757:PAX5 Transcription Factor / Q000378:metabolism*; D016539:Reed-Sternberg Cells / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology; D015534:Trans-Activators / Q000378:metabolism*
D014408:Biomarkers, Tumor; D050813:Octamer Transcription Factor-2; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human; C091546:POU2AF1 protein, human; D015534:Trans-Activators