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. Rationale: 1. KMT2A rearrangement is a genetic abnormality commonly associated with acute leukemia. 2. Presence of blasts (14%) with monocytic appearance and positive for CD33 also supports the diagnosis. 3. The percentage of blasts (14%) is not below the threshold for acute leukemia diagnosis. 4. The specific cytogenetic findings mentioned in choice C are not absolute requirements for diagnosing acute leukemia. In summary, the presence of KMT2A rearrangement, along with morphologic and flow cytometry findings, supports the diagnosis of acute leukemia in this case, making choice D the correct answer.

Correct Answer: C

Rationale: Rationale: C: Progressive loss or thinning of hair occurs in the geriatric population due to age-related changes in the hair follicles. As individuals age, the hair follicles shrink, leading to hair thinning or loss. Incorrect Choices: A: Dentition deteriorating with more cavities is related to oral health, not the hematologic system. B: Strong and smooth nails are not directly related to age-related changes in the hematologic system. D: Sclerae turning yellow or pale is indicative of potential liver dysfunction, not a direct age-related change in the hematologic system.

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: D

Rationale: The correct answer is D: Monocytosis. In chronic bacterial infections, monocytosis occurs due to the increased presence of monocytes in response to the persistent infection. Monocytes differentiate into macrophages to help eliminate the bacteria. Neutrophilia (A) is more common in acute bacterial infections. Basophilia (B) is associated with conditions like chronic myeloid leukemia, not bacterial infections. Lymphocytosis (C) is often seen in viral infections or chronic inflammatory conditions, not specifically in chronic bacterial infections.

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.