Introduction: Waldenström's macroglobulinaemia is a rare B cell lymphoproliferative disorder characterized by lymphoplasmocyte bone marrow infiltration and monoclonal IgM gammopathy. In the majority of cases, Waldenström's macroglobulinaemia is a chronic disease with variable course. Therapy consists of alkylating agents, purine analogs and antiCD20 monoclonal antibody. In the literature, there have been descriptions of rare cases of progression of Waldenström's macroglobulinaemia to aggressive lymphoma, as well as secondary carcinoma in the patients after treatment of macroglobulinaemia.
Case outline: A 63-year-old patient was diagnosed with serum monoclonal IgM kappa gammopathy (Waldenström's macroglobulinaemia). Chemotherapy was applied and a good clinical and haematological response had been achieved. Ten years later, the patient was diagnosed with colon adenocarcinoma as a secondary malignancy, and operated on. Within one month, the patient rapidly developed a large neck tumour mass. Tumour biopsy revealed the diagnosis of diffuse large B-cell lymphoma with the expression of monoclonal lambda chain, which more likely pointed out to coexistence of two different B cell lymphoproliferative disorders, rather than the transformation of Waldenström's macroglobulinaemia to aggressive lymphoma. The patient was treated with chemotherapy following R-CHOP protocol, and clinical remission was achieved. Seven months later, despite the successful treatment of lymphoproliferative disorder, dissemination of adenocarcinoma led to the lethal outcome.
Conclusion: The patient was diagnosed with a rare occurrence of three neoplastic diseases: Waldenstrom's macroglobulinaemia, colon adenocarcinoma and diffuse large B cell lymphoma. The possible mechanisms of the combined appearance of lymphoproliferative and other malignant diseases include the previous treatment with alkylating agents, genetic, immunomodulatory and environmental factors.