<prompt> A 61-year-old man gives a history of back pain for several months. A plain film radiograph of the spine reveals several 1 to 2 cm lytic lesions of the veebral bodies. He has no lymphadenopathy or splenomegaly on physical examination. Serum chemistries show sodium 140 mmolL, potassium 4.4 mmolL, chloride 101 mmolL, CO2 26 mmolL, glucose 78 mgdL, urea nitrogen 49 mgdL, creatinine 5 mgdL, total protein 8.3 gdL, albumin 3.7 gdL, alkaline phosphatase 176 UL, AST 45 UL, ALT 22 UL, and total bilirubin 1.2 mgdL. He recently developed a cough productive of yellowish sputum, and a sputum culture grew Streptococcus pneumoniae. During the course of his hospitalization, a bone marrow biopsy is performed. The biopsy is most likely to show:Scattered small granulomasNodules of small mature lymphocytesOccasional Reed-Sternberg cellsNumerous plasma cells  <response>: The findings suggest multiple myeloma. The renal failure and the increased risk for encapsulated bacterial infections is typical. 