Nokea
Platelet aggregation is an important event in hemostasis. Which of the following statement is true for platelet aggregation in vascular injury?
- A. There will be initial vasodilation
- B. Clotting factors play no role in its formation
- C. Platelets change their shape during the process
- D. Serotonin stimulates platelet aggregation
Correct Answer: C
Rationale: The correct answer is C: Platelets change their shape during the process of platelet aggregation in vascular injury. Platelets undergo shape change from a discoid to a spiky form, leading to the exposure of their glycoprotein receptors, which then bind to fibrinogen and other platelets to form a platelet plug. This process is crucial for hemostasis and preventing excessive bleeding.
Explanation for why other choices are incorrect:
A: There will be initial vasodilation - Vasodilation is not a direct result of platelet aggregation but rather an initial response to vascular injury to increase blood flow to the area.
B: Clotting factors play no role in its formation - Clotting factors are essential for the later stages of hemostasis, but platelet aggregation is primarily driven by platelet activation and shape change.
D: Serotonin stimulates platelet aggregation - While serotonin is released from platelets upon activation, it does not directly stimulate platelet aggregation.
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A 9-year-old boy presents to the emergency department with emesis and headache of 3 weeks' duration. MRI reveals a large heterogeneous mass in the cerebellum. He undergoes a resection, and the pathology is most consistent with a classic medulloblastoma. Which of the following findings would classify the patient as a high-risk medulloblastoma?
- A. Elevated serum and CSF AFP and beta-HCG tumor markers
- B. WNT subgrouping on molecular classification
- C. A presurgical spine MRI that reveals bulky tumor in the spine
- D. A postoperative brain MRI with no signs of residual tumor
Correct Answer: C
Rationale: The correct answer is C. A presurgical spine MRI revealing bulky tumor in the spine classifies the patient as high-risk due to leptomeningeal spread. This indicates dissemination of the tumor cells beyond the primary site, leading to a poorer prognosis. Choice A is incorrect as AFP and beta-HCG markers are associated with germ cell tumors, not medulloblastomas. Choice B is incorrect as WNT subgrouping is associated with better outcomes. Choice D is incorrect because the absence of residual tumor postoperatively does not necessarily indicate high-risk disease.
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?
- A. Bone Scan
- B. Lumbar puncture for cerebrospinal fluid cytology
- C. Bone marrow aspirate and biopsy
- D. Ga 68-DOTATATE PET/CT
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.
A client is having a radioisotopic imaging scan. What action by the nurse is most important?
- A. Assess the client for shellfish allergies.
- B. Place the client on radiation precautions.
- C. Sedate the client before the scan.
- D. Teach the client about the procedure.
Correct Answer: D
Rationale: The correct answer is D because educating the client about the procedure is crucial for informed consent, cooperation, and reducing anxiety. This empowers the client to participate actively in their care. Assessing for shellfish allergies (A) is irrelevant unless a specific contrast agent is used. Placing the client on radiation precautions (B) is unnecessary for radioisotopic imaging. Sedating the client (C) may not be indicated and should be avoided if possible. Teaching the client about the procedure (D) addresses the immediate need and supports client safety and understanding.
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?
- A. CXCR4
- B. ELANE
- C. GATA 2
- D. Mitochondrial DNA
Correct Answer: A
Rationale: The correct answer is A: CXCR4. In this case, the familial inherited bone marrow failure syndrome with severe neutropenia, recurrent infections, and warts suggests WHIM syndrome. WHIM syndrome is caused by a gain-of-function mutation in the CXCR4 gene, leading to impaired neutrophil trafficking. The symptoms and bone marrow findings in this patient align with WHIM syndrome. Choice B (ELANE) is associated with cyclic neutropenia, not WHIM syndrome. Choice C (GATA 2) is linked to familial myelodysplastic syndromes and acute myeloid leukemia, not WHIM syndrome. Choice D (Mitochondrial DNA) is not associated with WHIM syndrome. Therefore, the mutation in CXCR4 is the most likely cause of the familial inherited bone marrow failure syndrome in this patient.
A 19-year-old freshman in college presents with 'lumps' on the right side of his neck and in the right axilla. He had a fever to 39 °C 1 day in the past week. On physical exam, there are firm anterior cervical and axillary nodes, all greater than 2 cm in diameter. A chest x-ray shows a large mediastinal mass. A biopsy of the axillary node reveals classic Hodgkin lymphoma. Which of the following symptoms revealed during the history is a B symptom?
- A. Fever to 39 °C
- B. 10% weight loss in past 6 months
- C. Fatigue
- D. Alcohol-induced pain
Correct Answer: B
Rationale: The correct answer is B: 10% weight loss in the past 6 months. In Hodgkin lymphoma, B symptoms include unexplained weight loss of more than 10% in the past 6 months, fever >38°C, and night sweats. Weight loss is a significant indicator of systemic illness and malignancy. In this case, the patient's weight loss, along with the presence of fever and lymphadenopathy, fulfills the criteria for B symptoms in Hodgkin lymphoma. Choices A, C, and D are incorrect because fever, fatigue, and alcohol-induced pain are not specifically classified as B symptoms in the context of Hodgkin lymphoma. Fever alone does not qualify as a B symptom unless it is associated with other systemic symptoms like weight loss and night sweats. Fatigue can be a nonspecific symptom in many conditions, and alcohol-induced pain is not a recognized B symptom in Hodgkin lymphoma.