Fine needle aspiration cytology in the diagnosis of head and neck masses: accuracy and diagnostic problems

Abstract

Purpose: Fine needle aspiration (FNA) cytology is an established technique associated with minimal complications compared with more invasive techniques such as wide core needle biopsy or open biopsy, and as such, very suitable for obtaining material in the delicate region of head and neck (H&N). The aim of this study was to assess the diagnostic accuracy of FNA cytology H&N masses.

Methods: Aspirations were performed by cytologists using 25 or 27G needles with 20 ml syringes attached, and smears were stained with May-Grunwald-Giemsa. Four hundred and ninety-four patients with palpable H&N masses underwent FNA during the study period of 2 years.

Results: Based on cytology alone, the most common findings were reactive lymphoid hyperplasia (28.5%), metastatic carcinoma (22.7%) and lymphoma (13.4%). Sixty-four (12.6%) FNA specimens were inadequate for diagnosis. Histological correlation was available in 164 (33.2%) patients who went on to have surgical excision of the mass. Nondiagnostic aspirate was in 16 (9.75%) patients, so the final group for cyto- histological correlation included 148 patients. The overall accuracy rate of FNA cytology, whether malignant or benign, was 91.89%, while the diagnostic accuracy for the exact type of tumor was 87.16%. There were 3 (2%) false-positive (FP) and 9 (6.1%) false-negative (FN) cytological diagnoses. The sensitivity and specificity of FNA cytology in determining a malignant diagnosis were 91.5% and 92.85%, respectively. Positive (PPV) and negative predictive value (NPV) were 97 and 81.25%, respectively.

Conclusion: Our results showed that FNA cytology is a simple, safe, and cost-effective diagnostic method, suitable as a first-line investigation in palpable H&N masses. The main causes of the wrong diagnoses were sampling errors, inexperience and misinterpretation.