A 66 year old man saw his local physician for severe lower back pain.He had tried homeopathy and chiropractic manipulation,but nothing seemed to help.An x-ray of the spine revealed a lytic lesion at the L4 level,with collapse of the vertebral body.A spinal fusion was done,and a biopsy was sent to surgical pathology.A representative section of the biopsy is shown in the accompanying photomicrograph.Which one of the following is the best diagnosis?

Question

Quizplus · Accepted Answer

Most of the cells in the biopsy can be identified as plasma cells,from their peripheral chromatin and the fan-shaped cytoplasm.The lytic lesion of the spine is typical.If serum electrophoresis were available,it would show a monoclonal spike of gamma globulin,due to immunoglobulin synthesis by the neoplasm.

A 66 Year Old Man Saw His Local Physician for Severe