Plasmacytoma is a tumor of plasma cells but its manifestation is as localized tumor as compared to multiple myeloma which is also a plasma cell malignancy and manifest in a generalized manner. Solitary plasmacytoma is treated by radiation. But it may relapse in future. The majority of patients with solitary plasmacytoma develop myeloma. But when solitary plasmacytoma will convert into myeloma is uncertain and variable. It is difficult to estimate time. It develops early in patients who are more than 60 years old. Precautions 1. Be watchful for any bone pain or bone fracture 2. Regular estimate blood hemoglobin level. A falling trend is serious 3. Regularly check serum creatinine and calcium 4. Regularly do R/E of urine for Bence Jones urinary protein in urine 5. Be careful if getting repeated infection 6. Regularly check serum or urinary level of monoclonal protein Thanks