RESUMO
BACKGROUND: Monoclonal gammopathy is commonly associated with plasma cell dyscrasia. However, monoclonal gammopathy without bone marrow plasmacytosis in prostate carcinoma has rarely been reported. The association between the two conditions is not clearly established. CASE PRESENTATION: We report a case of metastatic prostate carcinoma in a 65-year-old Indian man with the unusual phenomenon of monoclonal band in gamma globulin region without evidence of bone marrow plasmacytosis. CONCLUSIONS: Monoclonal gammopathy in solid tumor has seldom been reported. This case report highlights the rare association of monoclonal gammopathy with malignant prostatic carcinoma. Therefore, while investigating a case such as this, in an elderly male patient, we should always keep a lookout for any solid tumor foci after excluding multiple myeloma.