A patient with suspected tuberculosis (TB) presents with cough, weight loss, night sweats, and hemoptysis. Chest X-ray reveals upper lobe infiltrates and cavitation. Which of the following diagnostic tests is most appropriate for confirming the diagnosis of pulmonary TB?

Correct Answer: A

Rationale: In a patient with suspected pulmonary TB, the most appropriate diagnostic test for confirming the diagnosis is the sputum acid-fast bacilli (AFB) smear and culture. This test involves examining sputum samples under the microscope for the presence of acid-fast bacilli, which are characteristic of Mycobacterium tuberculosis, the bacteria that causes TB. Additionally, culturing the sputum allows for the bacteria to grow in a controlled environment, further confirming the diagnosis. In the given scenario, the patient's symptoms (cough, weight loss, night sweats, hemoptysis), along with chest X-ray findings of upper lobe infiltrates and cavitation, are highly suggestive of pulmonary TB. Therefore, performing a sputum AFB smear and culture is crucial for definitive diagnosis and initiation of appropriate treatment. The other options (Tuberculin skin test, Interferon

Correct Answer: D

Rationale: The patient is presenting with symptoms and laboratory findings consistent with a paraneoplastic syndrome related to Hodgkin lymphoma. In this case, the fever, chills, generalized malaise, pancytopenia, circulating Reed-Sternberg cells, and bone marrow involvement are all indicative of a paraneoplastic syndrome associated with Hodgkin lymphoma. Paraneoplastic syndromes are a group of disorders that are triggered by an abnormal immune response to a neoplasm, such as Hodgkin lymphoma, leading to various systemic manifestations.

Correct Answer: B

Rationale: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive disorder that leads to hemolytic anemia in response to oxidative stress. The patient's presentation of fatigue, weakness, and jaundice along with laboratory findings of hemolytic anemia (evidenced by schistocytes), elevated LDH, and decreased haptoglobin are all characteristic of G6PD deficiency. The oxidative stress causes red blood cell destruction, resulting in the release of LDH and bilirubin, leading to jaundice. Decreased haptoglobin is seen due to its consumption in binding free hemoglobin released from the lysed red blood cells. Additionally, the presence of schistocytes on a peripheral blood smear is indicative of red blood cell fragmentation, a common finding in hemolytic anemias including G6PD deficiency

Correct Answer: D

Rationale: The presentation of sudden-onset severe headache, vomiting, and altered mental status, along with the presence of a berry-shaped aneurysm on imaging, point towards a diagnosis of subarachnoid hemorrhage. The most common cause of a subarachnoid hemorrhage is the rupture of a saccular (berry) aneurysm, which commonly occurs at the junction of the anterior communicating artery and anterior cerebral artery. The sudden headache is often described as the "worst headache of my life" and is typically associated with nausea and vomiting. Altered mental status may be present due to the effects of increased intracranial pressure and possible associated brain injury. It is important to promptly diagnose and manage subarachnoid hemorrhage to prevent complications such as vasospasm, rebleeding, and ischemic deficits.

Correct Answer: C

Rationale: A pituitary adenoma is a type of benign tumor that arises from the pituitary gland, which is located at the base of the brain. When a pituitary adenoma grows large enough, it can compress surrounding structures, including the optic chiasm – the point at which the optic nerves cross over in the brain. Compression of the optic chiasm can lead to symptoms such as vision problems (e.g., visual disturbances), headaches, and nausea/vomiting, which are consistent with the presentation described in the question. Meningiomas, glioblastoma multiforme, and medulloblastomas are less likely to compress the optic chiasm and present with different characteristic symptoms based on their locations and growth patterns.