Neoplasia USMLE Step 1 Practice Question
A 52-year-old man with a 40-pack-year smoking history presents to the emergency department with hemoptysis and dyspnea for 2 weeks. Vital signs include BP 128/82 mmHg, HR 102 bpm, RR 22/min, and SpO2 92% on room air. Chest X-ray reveals a 3-cm mass in the right upper lobe with no cavitation. CT chest shows mediastinal lymphadenopathy but no distant metastases. Bronchoscopic biopsy demonstrates small, round neoplastic cells with dense hyperchromatic nuclei, scant cytoplasm, and frequent mitoses. Immunohistochemistry is positive for synaptophysin and chromogranin A. Laboratory studies show serum LDH of 520 U/L (normal <400) and normal serum calcium. Which of the following best characterizes the biologic behavior of this malignancy?
Answer choices
- ASlow growth rate with late hematogenous dissemination and 5-year survival exceeding 50%
- BPredilection for endobronchial spread with preservation of pulmonary function until advanced stages
- CRapid doubling time with early hematogenous dissemination and poor overall prognosis despite chemotherapyCorrect answer
- DTendency for superior vena cava syndrome as initial presenting manifestation due to mediastinal involvement
- EFrequent paraneoplastic syndromes including hypercalcemia and hyponatremia as primary clinical features
- FPredominately peripheral location with skeletal metastases and osteoblastic bone lesions
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