A patient is presented with weakness of legs, arms, trunk, tingling and numbness that progressively worsens. Peripheral blood smear shows macrocytic anemia. Which of the following is not the factor causing this condition?

Correct Answer: C

Rationale: The correct answer is C: Tapeworm infestation. The symptoms described are consistent with vitamin B12 deficiency, which can result in macrocytic anemia and neurological symptoms. Chronic atrophic gastritis and ileal resection can impair absorption of vitamin B12, leading to deficiency. Alcoholism can also lead to malnutrition and vitamin deficiencies. Tapeworm infestation, on the other hand, does not directly affect vitamin B12 absorption. Therefore, tapeworm infestation is not a factor causing the condition described.

Correct Answer: A

Rationale: The correct answer is A: Filovirus. Viral hemorrhagic fevers are caused by viruses within the Filovirus family, which includes Ebola and Marburg viruses. Symptoms such as fever, vomiting, hypotension, and facial edema are characteristic of these infections. Togavirus (choice B) does not typically cause hemorrhagic fevers. Adenovirus (choice C) and Bunyavirus (choice D) are not commonly associated with viral hemorrhagic fevers. Therefore, the suspected virus in this patient most likely belongs to the Filovirus family.

Correct Answer: D

Rationale: The correct answer is D: Glucose 6-phosphate dehydrogenase deficiency (G6PD). Sulfonamides can trigger hemolysis in patients with G6PD deficiency due to oxidative stress on red blood cells. G6PD enzyme deficiency impairs the ability of red blood cells to combat oxidative damage, leading to hemolysis. In this case, the patient's hemoglobin decreased significantly after sulfonamide treatment, indicating red blood cell destruction. The other choices (A: Sickle cell disease, B: Thalassemia minor, C: Hereditary spherocytosis) are not directly associated with sulfonamide-induced hemolysis and would not explain the observed decrease in hemoglobin levels after treatment.

Correct Answer: D

Rationale: The correct answer is D: Myelodysplastic syndrome. The patient's symptoms of weakness, lassitude, and reduced erythropoiesis along with increased myeloblasts in bone marrow are indicative of a myelodysplastic syndrome. This condition is characterized by ineffective hematopoiesis leading to cytopenias and an increased risk of progression to acute myeloid leukemia. Acute myeloid leukemia (choice A) typically presents with more aggressive symptoms and higher blast count. Acute lymphoid leukemia (choice B) primarily affects lymphoid cells, not myeloid cells. Myelofibrosis (choice C) is characterized by fibrosis in the bone marrow, leading to extramedullary hematopoiesis, which is not seen in this case.

Correct Answer: B

Rationale: Step 1: Non-Hodgkin lymphoma (NHL) can arise from either B cells or T cells. B cell NHL is more common than T cell NHL. Step 2: The B cell phenotype is predominant in NHL, making choice B correct. Step 3: Classical Reed-Sternberg cells are characteristic of Hodgkin lymphoma, not NHL, making choice A incorrect. Step 4: NHL can involve non-contiguous lymph nodes, ruling out choice C. Step 5: NHL can present with leukemic involvement, refuting choice D. Overall, the B cell phenotype being more common in NHL makes choice B the correct answer.