You have a new 7-year-old female patient with a WBC count of 6,000/mm3, hemoglobin of 7.2 g/dL, and platelet count of 30,000/mm3. A bone marrow aspirate reveals 14% blasts with a monocytic morphologic appearance that are surface marker positive for CD33. You receive a call from the fluorescence in situ hybridization (FISH) lab that the bone marrow is positive for KMT2A rearrangement in 68% of cells. Your staff asks whether this represents a diagnosis of acute leukemia in the current classification scheme for this type of hematologic malignancy. What would you say?

Correct Answer: D

Rationale: The correct answer is D: Yes, because the FISH is positive for KMT2A rearrangement. The presence of KMT2A rearrangement in 68% of cells indicates a specific genetic abnormality associated with acute leukemia. This abnormality is a known marker for acute myeloid leukemia (AML) with recurrent genetic abnormalities. The percentage of blasts in the bone marrow (14%) may not meet the traditional criteria for a diagnosis of acute leukemia based on blast percentage alone, but the presence of KMT2A rearrangement overrides this requirement in this case. Choices A and B are incorrect because blast percentage alone is not the sole determinant of a diagnosis of acute leukemia when specific genetic abnormalities are present. Choice C is incorrect because while the absence of specific cytogenetic abnormalities may be relevant for some cases, the presence of KMT2A rearrangement is sufficient to support a diagnosis of acute leukemia in this context.

Correct Answer: C

Rationale: Rationale: Correct Answer (C): Progressive loss or thinning of hair is an age-related change in the hematologic system due to decreased blood flow to hair follicles. This is commonly observed in the elderly population. Incorrect Choices: A: Dentition deteriorates with more cavities is related to dental health, not the hematologic system. B: Nails being strong and smooth are related to nail health, not the hematologic system. D: Sclerae turning yellow or pale is a sign of jaundice, which is related to liver function, not the hematologic system.

Correct Answer: C

Rationale: The correct answer is C: Tapeworm infestation. The symptoms described suggest vitamin B12 deficiency, which can lead to macrocytic anemia. Chronic atrophic gastritis can cause decreased intrinsic factor production, leading to impaired B12 absorption. Ileal resection can also affect B12 absorption as it is the site where B12 is absorbed. Alcoholism can lead to poor dietary intake and impaired B12 absorption. However, tapeworm infestation does not directly affect B12 absorption and would not be a likely cause of the described symptoms.

Correct Answer: D

Rationale: The correct answer is D: Monocytosis. In chronic bacterial infections, there is a prolonged immune response leading to an increased production of monocytes to help combat the infection. Neutrophilia (choice A) is more characteristic of acute bacterial infections. Basophilia (choice B) is associated with allergic reactions or certain blood disorders, not typically seen in bacterial infections. Lymphocytosis (choice C) is more common in viral infections or certain immune responses, not specific to chronic bacterial infections.

Correct Answer: A

Rationale: The correct answer is A: Filovirus. Filoviruses, such as Ebola and Marburg viruses, are known to cause viral hemorrhagic fevers and are commonly found in Africa. The symptoms presented by the patient align with those of filovirus infections. Togavirus (choice B) and Bunyavirus (choice D) are not typically associated with viral hemorrhagic fevers. Adenovirus (choice C) can cause respiratory and gastrointestinal infections but is not known to cause viral hemorrhagic fevers.