An 86-year-old female, an ex-smoker, presents with chest discomfort and dyspnea.
Bronchoscopy with mediastinal staging, radial EBUS/fluoroscopy, and tumor sampling revealed moderately differentiated squamous cell carcinoma, staged as T2bN0M0, Stage IIA.
H&E-stained sections reveal multiple fragments of airway, with one fragment showing infiltrative nests of pleomorphic squamoid cells. A few mitotic figures are identified within a background of fibrous stroma. Immunohistochemistry for p40, TTF-1, and synaptophysin demonstrated that the cells were positive for p40 and negative for the other markers.