Is repeat fine needle aspiration required in thyroid nodules with initial benign cytology? Results from a large Irish series.

BACKGROUND : Fine needle aspiration (FNA) cytology is the preferred method for assessing thyroid nodules for malignancy. Concern remains about the rate of false negative results. The primary aim of this study is to investigate the malignancy rate of thyroid nodules initially classified as benign (Thy 2). METHODS: We retrospectively examined 658 nodules in 653 (429 female) patients between January 2013 to December 2017. All FNA biopsies (FNABs) were performed under ultrasound (US) guidance by a radiologist with expertise in thyroid pathology. Nodules were cytologically classified according to the UK Royal College of Pathologists guidelines. Decisions about further management were made at a regular thyroid multidisciplinary meeting. Follow up of the Thy 2 nodules was determined based on clinical and radiological criteria. RESULTS: The mean age (± SD) was 53.2 (14.6) years. Five hundred out of 658 (76.0%) nodules were classified as Thy 2 (benign) after the first FNAB. Of these thyroid nodules initially classified as benign, 208 (41.6%) underwent repeat FNAB and 9 (1.8%) were surgically removed without repeat FNAB. The remainder were followed up clinically and/or radiologically. Seven (1.4%) of nodules initially classified as Thy 2 were later shown to be or to harbor malignancy after a follow-up of 74.5 (± 19.7) months. Papillary thyroid microcarcinomas were found co-incidentally in two thyroid glands of benign nodules, giving a true prevalence of 5/500 (1.0%). CONCLUSIONS: With a well targeted FNAB, the false negative rate of an initial benign thyroid FNA is very low thus routine second FNAB is not required in patients with a thyroid nodule initially deemed benign. Multidisciplinary input is imperative in informing decision making.

The diagnostic utility of late night salivary cortisol (LNSF) and cortisone (LNSE) in Cushing's syndrome.

BACKGROUND: Measurement of late night salivary cortisol (LNSF) is useful in the identification of cyclical Cushing's syndrome (CS); the usefulness of its metabolite cortisone (late night salivary cortisone, LNSE) is less well described. AIM: The aim of this study was to determine the utility of measuring LNSE in patients with confirmed CS compared with other diagnostic tests and to analyse serial LNSF measurements for evidence of variable hormonogenesis. METHODS: This was a retrospective observational study including patients with confirmed CS in whom LNSF and LNSE were measured. RESULTS: Twenty-three patients with confirmed CS were included, 21 with Cushing's disease. LNSF had a sensitivity of 92%, LNSE 87% and combined LNSF/LNSE 94% per sample. Four patients had cyclical hormonogenesis, when the definition of one trough and two peaks was applied to LNSF measurements, and a fifth patient fell just outside the criteria. Six patients had evidence of variable hormonogenesis, defined as doubling of LNSF concentration on serial measurements. Sensitivity of 24-h urinary free cortisol (UFC) was 89% per collection. Sixteen patients had simultaneous measurements of LNSF and UFC; in three patients, they provided discordant results. CONCLUSION: LNSF appears more sensitive than LNSE and UFC in the diagnosis of CS, combining LNSF and LNSE results leads to superior sensitivity. Half of our cohort had evidence of cyclical or variable hormonogenesis. Fluctuations in LNSF did not always correlate with changes in UFC concentration, emphasising the importance of performing more than one screening test, particularly if pretest clinical suspicion is high.