Fine-needle aspiration biopsy of the thyroid

Before the introduction of fine-needle aspiration biopsy (FNAB) for preoperative evaluation of scintigraphically "cold" and sonographically echo-decreased solitary nodules of the thyroid the incidence of malignancy in resected nodules was 10-25% (2). By aid of FNA-cytology the number of exploratory operations has been reduced by 50% and the carcinoma incidence in the group of patients who ore surgically treated has been doubled (1, 4). a further reduction of exploratory operations con be achieved through improving morphological diagnostics by additional methods, e.g. immonocytochemistry or molecular genetics (10). The choice of a certain additional method depends on the respective morphological problems encountered by the cytopathologist in association with the different tumor entities of the thyroid gland.