ATI RN
The Hematologic System ATI Questions
Question 1 of 5
You are consulting on a 10-year-old male with severe persistent neutropenia, a history of recurrent infections, and warts. The rest of the peripheral blood count is normal. His mother also has neutropenia. Bone marrow examination shows a hypercellular marrow and retained myeloid cells with vacuolated cytoplasm. There are no abnormalities in the red cells or platelet precursors. Cytogenetics are 46XY. You start granulocyte colony stimulating factor therapy and the neutrophil count increases. A mutation in which of the following genes is most likely to have caused this familial inherited bone marrow failure syndrome?
Correct Answer: A
Rationale: The correct answer is A: CXCR4. In this case, the patient presents with severe neutropenia, recurrent infections, and warts, suggestive of WHIM syndrome, where CXCR4 mutations are often involved. CXCR4 plays a crucial role in immune cell trafficking and retention in the bone marrow. The hypercellular marrow and vacuolated myeloid cells are consistent with WHIM syndrome. The absence of abnormalities in red cells or platelet precursors rules out other syndromes. Mutations in ELANE are commonly associated with congenital neutropenia, not familial inherited bone marrow failure syndromes. GATA2 mutations are linked to familial myelodysplastic syndromes, not typically presenting with neutropenia and warts. Mitochondrial DNA mutations are more related to mitochondrial disorders, which usually manifest with multi-system involvement, not specific to bone marrow failure syndromes.
Question 2 of 5
You have been asked to see a 15-year-old girl who is being referred for evaluation of an ovarian mass. Her history is also significant for secondary amenorrhea, and physical examination shows signs of virilization. As you review her family history, what syndrome will you consider?
Correct Answer: B
Rationale: The correct answer is B: DICER-1 syndrome. This syndrome is associated with ovarian tumors, secondary amenorrhea, and signs of virilization due to androgen-secreting tumors. Li-Fraumeni syndrome (A) is characterized by multiple primary cancers but not specifically ovarian masses. Turner syndrome (C) presents with ovarian dysgenesis and primary amenorrhea. Beckwith-Wiedemann syndrome (D) is associated with overgrowth and abdominal wall defects, not ovarian masses. In this case, the presence of ovarian mass, secondary amenorrhea, and virilization point towards DICER-1 syndrome.
Question 3 of 5
You are seeing a 12-year-old female who presented to the emergency department with the sudden onset of severe abdominal pain. Imaging that was obtained to rule out appendicitis revealed a mass adjacent to the bladder. The mass was surgically resected, and pathology demonstrated a paraganglioma. Which of the studies below would be most useful to determine disease stage for this patient?
Correct Answer: D
Rationale: The correct answer is D: Ga 68-DOTATATE PET/CT. Paragangliomas are neuroendocrine tumors that can secrete catecholamines and have a high expression of somatostatin receptors. Ga 68-DOTATATE PET/CT is the most appropriate imaging study to determine disease stage in patients with paragangliomas because it can detect the somatostatin receptor expression in these tumors, aiding in localization, staging, and treatment planning. A: Bone scan is not the most useful study for determining disease stage in paraganglioma. B: Lumbar puncture for cerebrospinal fluid cytology is not relevant for staging paraganglioma. C: Bone marrow aspirate and biopsy are not the most appropriate studies for staging paraganglioma.
Question 4 of 5
A 2-month-old girl is found to have a small, hard mass on her scalp. The mass increases in size over the next 4 weeks. A biopsy is performed that confirms a diagnosis of embryonal rhabdomyosarcoma. You initiate chemotherapy with vincristine, dactinomycin, and cyclophosphamide. The child presents to clinic for day 1 of cycle 3 of chemotherapy, and the mass on her scalp is smaller. She is afebrile, absolute neutrophil count is 1,405 cells/mcL, platelet count is 154,000/mcL, and total bilirubin is 0.8 mg/dL. Her mother reports she looks very tired because her eyelids have been 'very droopy,' and she thinks she has a sore throat because her cry is hoarse. Her last bowel movement was 2 days ago. What is the most appropriate chemotherapy plan?
Correct Answer: C
Rationale: The correct answer is C: Administer dactinomycin and cyclophosphamide but hold the vincristine and reevaluate weekly. If the ptosis and hoarse cry resolve, vincristine can be resumed with a dose reduction and, if tolerated, re-escalated to the full dose in the future. Rationale: 1. Ptosis and hoarse cry are symptoms of vincristine-induced neurotoxicity. 2. Holding vincristine allows for resolution of these side effects. 3. Reevaluating weekly ensures close monitoring of symptoms. 4. If symptoms resolve, vincristine can be cautiously reintroduced with a dose reduction to prevent further neurotoxicity. Summary: A: Continuing all chemotherapy may worsen neurotoxicity. B: Withholding all chemotherapy is not appropriate if two agents are effective. D: Discontinuing vincristine permanently may limit treatment options.
Question 5 of 5
Which of the following is a key feature of Factor XIII?
Correct Answer: A
Rationale: The correct answer is A: Its half-life is about 10 days. Factor XIII has a long half-life due to its stable tetrameric structure, allowing it to circulate in the blood for about 10-14 days. This extended half-life is crucial for its role in stabilizing fibrin clots. Explanation for why other choices are incorrect: B: Factor XIII is not an activator of thrombin; rather, it crosslinks fibrin strands to strengthen clots. C: Factor XIII levels are low in newborns and gradually increase during the first few months of life. D: Factor XIII is not part of the contact activation system, which involves factors XII, XI, and prekallikrein.