Carcinomatous lung abscess. Diagnosis by bronchoscopy and cytopathology.

We compared the roentgenographic, bronchoscopic, and cytopathologic findings from 26 patients with carcinomatous lung abscesses (23 of which were within the tumor) with findings from 31 patients with simple lung abscesses. Despite well-described roentgenographic characteristics of the carcinomatous abscess, differentiation from a simple abscess was frequently not possible. Direct visual findings at the time of bronchoscopy were not helpful in the absence of an endobronchial lesion. Using sputums and cytological specimens from a single fiberoptic bronchoscopy, a diagnosis was made by cytopathology on initial hospitalization in 22 (88%) of 25 patients with carcinoma. No false-positive cytological studies were reported in the nonmalignant group despite the frequent presence of inflammation and infection.