THE VALUE AND LIMITATIONS OF FINE-NEEDLE ASPIRATION CYTOLOGY IN THYROID NODULAR DISEASE

The results of thyroid aspiration in a cytology unit handling over 350 specimens a year were assessed. Of those aspirates performed by refer ring surgeons, 31% were inadequate or unsatisfactory compared with a 7 % unsuitability rate achieved when cytopathologists were aspirators. A nalysis of those patients in whom histological or long-term clinicorad iological follow-up was available, inclusive and exclusive of suspicio us cases respectively, demonstrated a sensitivity of 84 - 86%, specifi city of 93 - 98%, with positive predictive values of 82 - 94%, negativ e predictive values of 94% and efficacy of 91 - 99%. Fine-needle aspir ation identified 14,8% of patients examined as requiring surgery for s uspicious or malignant disease cytology. Of these, 82% were found to h arbour neoplasms. In contrast, of those in whom surgical excision was performed for reasons other than cytological abnormality, 6% were foun d to have neoplasia. This confirms the selection role of thyroid aspir ation cytology. The question of the false-negative aspirate is discuss ed.