Seeding of malignant cells into the needle track after lung and pleural biopsy.

Transthoracic needle biopsy is frequently performed for the diagnosis of pulmonary and pleural disease. Seeding of malignant cells is a potential complication but is extremely uncommon. We report the second patient with malignant seeding after fine-needle aspiration biopsy of a bronchogenic carcinoma. We also report a patient with seeding of bronchogenic carcinoma after a pleural biopsy. Because seeding is a rare complication, it does not affect the indications for biopsy.