A 62-year-old man with a 40-pack-year smoking history presents to the emergency department with hemoptysis and dyspnea. Chest X-ray shows a central lung mass with post-obstructive pneumonia. Bronchoscopy reveals a polypoid lesion obstructing the left mainstem bronchus with friable, bleeding tissue. Biopsy demonstrates small, round cells with scant cytoplasm, dense chromatin, and frequent mitotic figures. Immunohistochemistry is positive for synaptophysin and CD56. Which of the following is the most likely diagnosis?
- A)Typical carcinoid tumor (low-grade neuroendocrine carcinoma)
- B)Large cell neuroendocrine carcinoma
- C)Squamous cell carcinoma of the lung
- D)Adenocarcinoma with neuroendocrine differentiation
- E)Small cell lung cancerGABARITO
Explicação
Small cell lung cancer (SCLC) is the most likely diagnosis. The key diagnostic features are: (1) small, round cells with scant cytoplasm and high nuclear-to-cytoplasmic ratio; (2) dense chromatin ('salt-and-pepper' appearance); (3) frequent mitoses; (4) neuroe... Ver explicação completa e trilha adaptativa →