Small cell anaplastic carcinoma: cytological-histological correlations from percutaneous fine-needle aspiration biopsy.

Small cell anaplastic carcinoma (SCAC) is usually treated non-surgically and, therefore, diagnosis is best done by the least invasive means. Percutaneous fine-needle aspiration biopsy is very accurate in diagnosing malignancy and reasonably accurate in diagnosing malignant cell type. An unequivocal cytological diagnosis of SCAC has a positive predictive value of 0.90 at our institution. The accuracy is lowered by uncertain or suggestive cytological diagnoses.