A patient is presented with fever, vomiting, hypotension and facial edema after his business trip back from Africa. Viral hemorrhagic fever is suspected in this patient. Which of the following family does the suspected virus belong to?

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: 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.

Correct Answer: B

Rationale: The correct answer is B: Promastigote. In the laboratory diagnosis of leishmaniasis, the parasite stage typically observed in vitro is the promastigote stage. This is because promastigotes are the infective form of the parasite found in the sandfly vector. When a sample is taken from a patient, it is cultured in a suitable medium where promastigotes develop. Amastigotes (choice A) are the intracellular form found in the host, not typically observed in vitro. Trypomastigotes (choice C) are the stage found in Trypanosoma species, not Leishmania. Schizonts (choice D) are a stage in the life cycle of Plasmodium species causing malaria, not Leishmania. Promastigotes are the stage most commonly used for laboratory diagnosis and research in leishmaniasis.

Correct Answer: C

Rationale: Rationale: Hereditary spherocytosis is associated with splenomegaly due to the spleen's increased destruction of abnormal red blood cells. In this condition, red blood cells have a spherical shape, making them more prone to destruction by the spleen. Chronic renal failure (A) is not typically associated with splenomegaly. Aplastic anemia (B) is characterized by bone marrow failure and does not directly involve the spleen. Sickle cell anemia (D) leads to splenomegaly in children but not in adults due to splenic sequestration crises, making it less likely to be the correct choice.