This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plasma Cell Disorders and Multiple myeloma, Subject name: Pathology
[{'content': 'A 70-year-old male has a pathologic fracture of femur. The lesion appears a lytic on X-rays film with a circumscribed punched out appearance. The curetting from fracture site is most likely to show which of the following? \nSelect and explain. \nA. Diminished and thinned trabecular bone, B. Sheets of atypical plasma cells, C. Metastatic prostatic adenocarcinoma, D. Malignant cells forming osteoid bone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Old patient along with lytic circumscribed punched out X-ray appearance suggests multiple myeloma Multiple myeloma most often presents as multifocal destructive bone tumors composed of plasma cells throughout the skeletal system. It shows sheets of atypical plasma cells.', 'role': 'assistant'}]