A case of transformation of Waldenström's Macroglobulinemia to diffuse large B cell lymphoma.

Waldenström's Macroglobulinemia (WM) is a lymphoplasmacytic lymphoma which can rarely transform into diffuse large B cell lymphoma (DLBCL). Usually, the diagnosis of WM precedes DLBCL. A 79-year-old male presented to the hospital for worsening dysphagia and shortness of breath due to a rapidly growing base of tongue mass detected by CT scan. The mass was thought initially to be isolated DLBCL, though incidentally, markedly elevated IgM titers were noted. Biopsy of bone marrow and mass were consistent with histological transformation of WM to DLBCL. Response to treatment was assessed by the size of tongue mass on interval CT scans and IgM levels, both of which responded rapidly to chemotherapy. However, the patient developed early CNS relapse, consistent with the overall poor prognosis of transformed WM.