Fine-needle aspiration cytology findings in 214 cases of nonparotid lesions of the head

The use and limitations of fine-needle aspiration (FNA) of lesions of the p arotid gland are known, bur those of nonparotid lesions of the head have be en described only sporadically. We conducted this study to evaluate the uti lity of FNA and to analyze the causes of diagnostic discrepancies for these lesions. A total of 6,898 FNAs of different sites was performed at our ins titutions between January, 1991-August 1998, and 214 (3.1%) of the cases we re FNAs of nonparotid lesions of the head. The most common diagnosis of non parotid lesions was squamous-cell carcinoma, in 22% (n = 48), and the most common site aspirated was the scalp, in 34% (n = 73). Lipomas and keratinou s cysts comprised 5% (n = 9) of the total. A statistical analysis was condu cted on 98 paired cytology and histology (n = 83) and cytology and flow cyt ometry (n = 15) specimens (70 malignant and 28 benign). FNA recognized the malignant and benign nature of the lesion in 60 and 26 cases, respectively, with 86% sensitivity 93% specificity, and 88% accuracy. Causes of false-ne gative FNA diagnoses (n = 10) included sampling error (n = 6), bloody smear s with scant cellularity (n = 3), and bland cytomorphology (n = 1). Florid granulation tissue and mucocele of the tongue accounted for the two false-p ositive cases; We conclude that FNA is an effective tool for triage of surg ery candidates with nonparotid lesions of the head. Adequate samples with s ufficient cellularity are required for avoiding false-negative diagnoses. O ccasionally, tissue biopsy is needed for diagnosis of equivocal cases. (C) 2000Wiley-Liss,Inc.