Composite lymphoma of Hodgkin lymphoma and mycosis fungoides: previously undescribed in the same extracutaneous site.

Mycosis fungoides (MF), diagnosed and limited to the skin, has been associated with the subsequent development of Hodgkin lymphoma (HL), most commonly of the nodular sclerosing (NS) subtype. In the previously described cases, there are none in which the extracutaneous tissue was simultaneously involved by HL and residual/relapsing MF. Here we report a case of HL, mixed cellularity (MC) subtype, arising in an inguinal lymph node in a patient with a previous diagnosis of MF. We describe the immunophenotypic, histologic and immunohistochemical findings of a composite lymphoma containing the HL, MC subtype and MT. The importance of detecting MF in addition to the HL in the extracutaneous site with available diagnostic modalities is highlighted.