Hodgkin's lymphoma arising in a case of mycosis fungoides: An unusual association.

Mycosis fungoides is a cutaneous T-cell lymphoma with a high risk for developing secondary malignancies, especially B-cell lymphoproliferative disorders. About 40 cases of Hodgkin's lymphoma associated with mycosis fungoides have been reported in literature till date. We report a case of a 35-year-old gentleman who presented with intensely itchy reddish lesions all over the body. Multiple skin biopsies taken from the lesions on scalp and back confirmed the clinical diagnosis of mycosis fungoides. While on treatment, he presented with multiple bilateral cervical, axillary and inguinal lymphadenopathy 9 years after the primary diagnosis of mycosis fungoides. Excision biopsy of a cervical lymph node revealed partial effacement of architecture by a tumor comprising polymorphous background. Histopathology and immunohistochemistry revealed a diagnosis of Hodgkin's lymphoma - nodular sclerosis subtype. The patient was started on chemotherapy for stage IV Hodgkin's lymphoma. Our case emphasizes the importance of keeping secondary Hodgkin's lymphoma in mind while dealing with a patient of mycosis fungoides. Our case immunohistochemically supports the distinct etiopathogenesis of Epstein-Barr virus-negative Hodgkin's lymphoma vis-à-vis cutaneous mycosis fungoides.