Concurrent diagnoses of Hodgkin lymphoma and biclonal myeloma in the bone marrow

The diagnoses of Hodgkin lymphoma and multiple myeloma have rarely been made simultaneously in the same patient. We present a case of an 82-year-old man who rapidly developed pancytopenia and liver failure with coagulopathy. Serum protein electrophoresis and immunofixation revealed an unequivocal immunoglobulin Gκ and immunoglobulin Gλ biclonal gammopathy. Bone marrow biopsy showed involvement by classic Hodgkin lymphoma with an inflammatory background including 49% mature plasma cells. Unfortunately, the patient died 14 days after admission. To our knowledge, a case of concurrent Hodgkin lymphoma and biclonal multiple myeloma has not previously been reported. Detection of severe bone marrow plasmacytosis in the background of Hodgkin lymphoma should alert the pathologist to the possibility of collision with a plasma cell neoplasm, warranting a complete diagnostic workup.