2006 Volume 45 Issue 2 Pages 103-105
Background: Mixed mucinous and nonmucinous type bronchioloalveolar carcinoma (mixed BAC) fulfilling WHO criteria is extremely rare. We report a case of mixed BAC, focusing on cytology.
Case: A 57-year-old man was found in chest computed tomography (CT) to have a mass 3.0 cm in maximum diameter detected peripherally in the lower lobe of the right lung. Imprint smear cytology showed sheet-like clusters of atypical cells with or without mucin in cytoplasm, or of only nonmucinous atypical cells against a background of abundant mucin. Tumor cells of both components had similar nuclei with fine chromatin, distinct nucleoli, and the nuclear grooves typical of bronchioloalveolar carcinoma. A few psammoma bodies were observed. Histologically, the tumor consisted of atypical alveolar epithelium with lepidic growth along the alveolar wall and mucin in the alveolar space. Two types of neoplastic epithelium were identified: tall columnar cells with cytoplasmic mucin and cuboidal cells without mucin. No evidence was seen of stromal or pleural invasion.
Conclusion: Cytological findings are useful in diagnosing mixed BAC.
