Nokea
A 5-year-old boy presents with a 3-week history of his right eye “not moving to the right side.†The remainder of his neurologic exam is normal with the exception of a weak gag. MRI of the brain reveals a diffusely infiltrative mass in the pons. If this patient were to undergo a stereotactic biopsy, what would be the most likely molecular finding?
- A. BRAFKIAA1549 fusion
- B. Trisomy 21
- C. H3 K27M mutation
- D. RELA fusion
Correct Answer: C
Rationale: The correct answer is C: H3 K27M mutation. This mutation is most commonly associated with diffuse intrinsic pontine gliomas (DIPG), which are high-grade brain tumors typically found in children. The presence of a diffusely infiltrative mass in the pons in a 5-year-old boy with neurological symptoms points towards a DIPG. Stereotactic biopsy of the mass would likely reveal the H3 K27M mutation, which is a key molecular finding in DIPG.
Choice A (BRAFKIAA1549 fusion) is incorrect as this fusion is typically associated with pilocytic astrocytomas, not DIPGs. Choice B (Trisomy 21) is incorrect as it is not a molecular finding commonly associated with DIPGs. Choice D (RELA fusion) is also incorrect as this fusion is more commonly seen in ependymomas, not DIPGs.
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A 2-year-old girl has a diagnosis of overall stage IV favorable histology Wilms' tumor with pulmonary metastases and local stage III disease due to finding positive lymph nodes. After she completes 6 weeks of vincristine/dactinomycin/doxorubicin (DD4A) chemotherapy, restaging shows complete resolution of some but not all lung nodules. Tumor genetic testing reveals combined loss of heterozygosity for 1p and 16q. Which of the following would be the most appropriate treatment plan?
- A. Continue chemotherapy with vincristine, doxorubicin, and dactinomycin to complete 25 weeks of therapy. Administer radiation to lungs and flank.
- B. Continue chemotherapy with vincristine, doxorubicin and dactinomycin to complete 25 weeks of therapy. Radiation to flank only. No lung radiation.
- C. Continue chemotherapy with vincristine, doxorubicin and dactinomycin, add cyclophosphamide and etoposide to complete 33 weeks of therapy. Radiation to flank only. No lung radiation.
- D. Continue chemotherapy with vincristine, doxorubicin and dactinomycin, add cyclophosphamide and etoposide to complete 33 weeks of therapy. Radiation to lungs and flank.
Correct Answer: D
Rationale: The correct answer is D because the patient has residual lung nodules after initial chemotherapy, indicating a need for intensified treatment. Adding cyclophosphamide and etoposide to the chemotherapy regimen can improve outcomes in patients with combined loss of heterozygosity for 1p and 16q. Radiation to both the lungs and flank targets all remaining disease sites effectively.
Choice A is incorrect because it does not address the need for intensified treatment with additional agents or radiation to the lungs, where residual disease remains.
Choice B is incorrect as it only includes radiation to the flank and not the lungs, which are still harboring disease.
Choice C is incorrect because although it adds cyclophosphamide and etoposide, it does not include radiation to the lungs, which is necessary for comprehensive disease control.
Artemisinin and its derivatives are used in the treatment of severe forms of chloroquine-resistant falciparum because they have:
- A. Rapid gametocidal activity
- B. The ability to prevent further development of hypnozoites
- C. Rapid sporontocidal activity
- D. Rapid schizonticidal activity
Correct Answer: D
Rationale: The correct answer is D: Rapid schizonticidal activity. Artemisinin and its derivatives target the asexual stage of the malaria parasite's life cycle, specifically the schizont stage. By quickly destroying the schizonts, they effectively kill the parasites in the blood, leading to a rapid reduction in parasite load and alleviating symptoms. The other choices are incorrect because A (Rapid gametocidal activity) targets sexual stage parasites, B (Ability to prevent further development of hypnozoites) refers to relapse prevention in Plasmodium vivax and Plasmodium ovale infections, and C (Rapid sporontocidal activity) targets the mosquito stage of the parasite's life cycle.
A 12-year-old patient has been referred to you following complete resection with clean margins of a high-grade malignant peripheral nerve sheath tumor of the shoulder region. The tumor measured approximately 4 cm in greatest dimension. A CT scan of the chest and a bone scan were within normal limits. The patient does not have evidence of neurofibromatosis type 1 (NF1). Which of the following treatment approaches would you recommend?
- A. Chemotherapy with doxorubicin and ifosfamide
- B. Radiotherapy
- C. Chemotherapy with doxorubicin and ifosfamide plus radiotherapy
- D. Observation
Correct Answer: D
Rationale: The correct answer is D: Observation. Given the complete resection with clean margins, normal chest CT, bone scan, and absence of NF1, observation is appropriate. Chemotherapy or radiotherapy may be considered in the presence of residual disease, positive margins, or metastasis. Chemotherapy with doxorubicin and ifosfamide may cause unnecessary toxicity without clear benefit in this scenario. Radiotherapy may be reserved for cases with high-risk features. Combining chemotherapy and radiotherapy may lead to increased toxicity without proven benefit. Observation allows monitoring for disease recurrence while minimizing unnecessary treatment side effects.
A 13-year-old boy presents to the emergency department with complaints of headache and visual changes. History reveals progressive dyspnea on exertion, generalized fatigue, and increased bruising. His labs are significant for a WBC of 350,000/mcL, of which 80% are reported to be blasts and appear to be myeloblasts without the presence of Auer rods. His hemoglobin is 7.2 g/dL, and his platelets are 18,000/mcL. A CT scan of the head shows a small intracerebral hemorrhage. His coags are normal. Which of the following is the most appropriate therapy?
- A. Start induction chemotherapy.
- B. Perform emergent leukapheresis followed the next day by induction chemotherapy.
- C. Perform emergent leukapheresis plus hydroxyurea.
- D. Provide emergent cranial radiation plus hydroxyurea followed the next day by induction chemotherapy.
Correct Answer: C
Rationale: The correct answer is C: Perform emergent leukapheresis plus hydroxyurea. In this scenario, the patient presents with symptoms suggestive of acute myeloid leukemia with hyperleukocytosis and intracerebral hemorrhage. The goal of emergent therapy is to rapidly reduce the high blast count to prevent further complications such as leukostasis and hemorrhage. Leukapheresis can provide immediate reduction in the blast count, while hydroxyurea can further decrease the WBC count. Starting induction chemotherapy immediately can lead to tumor lysis syndrome due to rapid cell destruction. Emergent cranial radiation is not the primary intervention for hyperleukocytosis. Performing leukapheresis alone without adjunctive therapy like hydroxyurea may not adequately control the blast count. Thus, the most appropriate initial therapy is emergent leukapheresis plus hydroxyurea to stabilize the patient before initiating induction chemotherapy.
The nurse examines the lymph nodes of a patient during a physical assessment. Which assessment finding would be of most concern to the nurse?
- A. A 2-cm nontender supraclavicular node
- B. A 1-cm mobile and nontender axillary node
- C. An inability to palpate any superficial lymph nodes
- D. Firm inguinal nodes in a patient with an infected foot
Correct Answer: A
Rationale: The correct answer is A: A 2-cm nontender supraclavicular node. This finding is concerning because supraclavicular nodes are not normally palpable. Enlarged supraclavicular nodes can indicate metastatic cancer. B is incorrect because mobile and nontender axillary nodes are usually benign. C is incorrect as the inability to palpate superficial nodes may be normal. D is incorrect as firm inguinal nodes could indicate a localized infection or inflammation.