A 70-year-old man with back pain, fatigue, fever, Hb 7 g/dL, MCV 89 fL, high Ca, renal insufficiency. Definitive diagnosis best made by?

Correct Answer: D

Rationale: The correct answer is D: Greater than 30% plasma cells in bone marrow. This scenario is indicative of multiple myeloma, a plasma cell disorder. High Ca and renal insufficiency suggest hypercalcemia and kidney damage due to monoclonal protein deposition. Anemia and MCV suggest bone marrow involvement. Choice A is not specific for multiple myeloma. Choice B is used to evaluate bone metastasis. Choice C is invasive and not typically done for initial diagnosis of multiple myeloma. Therefore, D is the best option for definitive diagnosis in this case.

Correct Answer: D

Rationale: The correct answer is D: Adjuvant hormonal therapy. For ER/PR+ breast cancer, hormonal therapy is the standard treatment to reduce the risk of recurrence. This patient has a high-risk tumor with positive lymph nodes, making hormonal therapy crucial to target any remaining cancer cells. No further treatment (A) is not appropriate given the high-risk features. Radiation to mammary nodes (B) is not the standard of care for ER/PR+ breast cancer. Platinum chemotherapy (C) is not indicated for ER/PR+ breast cancer and is reserved for other subtypes.

Correct Answer: D

Rationale: The correct answer is D: No further testing. In this scenario, the patient has a clear risk factor for DVT (long flight) and is already on anticoagulation therapy. Further diagnostic tests are not necessary for the management of acute DVT in this case. Testing for Factor V Leiden or Protein C, S, antithrombin III levels would not change the management at this point. Antiphospholipid antibody test is not indicated as there are no signs or symptoms suggestive of antiphospholipid syndrome. The most appropriate action is to continue the current treatment and monitor the patient's response.

Correct Answer: A

Rationale: The correct answer is A: Thalassemia. Thalassemia is a genetic disorder characterized by reduced production of hemoglobin, leading to microcytic anemia. Normal iron studies in this case suggest that iron deficiency anemia (choice B) is unlikely. Sideroblastic anemia (choice C) is characterized by abnormal iron utilization, not normal iron studies. Anemia of chronic disease (choice D) typically presents with normocytic or mildly microcytic anemia and is associated with underlying chronic inflammatory conditions. Therefore, given the clinical presentation of microcytic anemia with normal iron studies in an 18-year-old man, thalassemia is the most likely diagnosis.

Correct Answer: A

Rationale: The correct answer is A because the absence of palpable radial/pedal pulses indicates poor perfusion, a critical concern in DIC. This finding suggests compromised blood flow, requiring urgent intervention to prevent tissue damage. Choices B, C, and D are not immediate concerns in DIC. Chest pain may indicate cardiac issues, but perfusion is the priority. Oxygen saturation at 87% is low but not as urgent as impaired perfusion. Mottling of hands and feet is a sign of poor perfusion but not as immediate as the absence of palpable pulses.