A patient with a history of multiple myeloma presents with weakness, bone pain, and recurrent infections. Laboratory tests reveal anemia, hypercalcemia, renal insufficiency, and monoclonal spike on serum protein electrophoresis. Which of the following conditions is most likely to cause these findings?
Correct Answer: D
Rationale: Multiple myeloma is a plasma cell neoplasm characterized by the presence of abnormal monoclonal plasma cells in the bone marrow, which produce a monoclonal spike on serum protein electrophoresis. The clinical presentation of weakness, bone pain, and recurrent infections is typical of multiple myeloma. Anemia can result from bone marrow infiltration by the abnormal plasma cells, hypercalcemia is due to bone destruction and release of calcium, renal insufficiency can result from hypercalcemia and protein deposition in the kidneys, and the monoclonal spike in serum protein electrophoresis indicates the presence of a monoclonal protein. Waldenström macroglobulinemia, Hodgkin lymphoma, and chronic lymphocytic leukemia do not typically present with the classic tetrad of findings seen in multiple myeloma.