Fine needle aspiration cytology of bronchioloalveolar-cell carcinoma of the lung.

The fine needle aspiration cytology features of twelve peripherally located bronchioloalveolar cell carcinomas of the lung diagnosed by fine needle aspiration biopsy are described. A spectrum of cytomorphologic changes was appreciated, including classic groups showing uniform malignant cells having prominent depth of focus with a lack of significant nuclear molding. Other cells showed features of atypical alveolar macrophages and bronchial-lining cells. The smears demonstrated malignant cells arranged along alveolar septae and possessing hobnail-shaped nuclei. Two cases had associated psammoma bodies, and one case demonstrated optically clear nuclei in the malignant cells. This series stresses the fine needle aspiration features that aid in the recognition of this specific lung neoplasm and its differentiation from benign reactive pulmonary lesions, other primary lung cancers and metastatic tumors.