ABSTRACT
We report a rare case of an 83-year-old male with synchronous occurrence of prostate adenocarcinoma and multiple myeloma. He presented with lower back pain and incontinence of urine for the past 6 months. Routine hematological and biochemical investigations were performed which pointed toward prostate adenocarcinoma. Transrectal ultrasonography and magnetic resonance imaging showed prostatomegaly along with osteolytic lesions in the skull and vertebrae. Prostate biopsy was performed and adenocarcinoma was confirmed. To rule out metastatic deposits in the bone and to rule out bone marrow infiltration, bone marrow aspiration and biopsy of the patient was done, and unexpectedly, it showed multiple myeloma. The association between these two disorders is poorly understood, but some studies show that bone marrow microenvironment plays an important role.