RESUMEN
BACKGROUND: Follicular lesion of undetermined significance (FLUS) was introduced for fine needle aspiration (FNA) cytology in which there is insufficient evidence to classify the lesion as follicular neoplasm/suspicious of follicular neoplasm or suspicious for malignancy. The recommended management was repeat FNA and correlation with clinical and radiological data. In 2009 we started a joint clinicopathological protocol to improve management of FLUS, recommending follow-up with repeat FNA at 6months. The aim of this study was to report on the audit of results of this protocol. METHODS: We reviewed the medical records of the patients with FLUS at a single hospital. Between 2007 and 2010 we found 135 cases with this diagnosis (3.6%). We only had long enough follow-up information for the 95 patients that were included in the present study. RESULTS: FLUS was diagnosed in 74 FNAs before protocol implementation (3.2%) and 61 FNAs after (4.2%), with follow-up of 46 and 49 patients, respectively. Before 2009, 38/46 (82.6%) patients had surgical excisions, compared with 32/49 (65.3%): a significant reduction of 17% in the number requiring surgery (P=0.05). We have also shown a reduction in the median time to surgery (11.9 versus 2.9 months). Despite the joint protocol, the FNA was only repeated in two patients. The histological diagnoses were similar in the two periods of time: 31.6% and 31.3% follicular adenomas; 13.1% and 3.1% (P=0.2) papillary carcinoma (follicular variant). CONCLUSIONS: Implementation of a joint protocol reduced the number of surgical operations in patients with FLUS but in most cases FNA was not repeated as recommended. Excision was justified in one-third of operated patients. Less than 15% of lesions were malignant, which is in accordance with previous reports in the literature.