UTILITY OF ULTRASOUND VERSUS GENE EXPRESSION CLASSIFIER IN THYROID NODULES WITH ATYPIA OF UNDETERMINED SIGNIFICANCE.

OBJECTIVE: Thyroid nodules with fine-needle aspiration (FNA) cytology categorized as atypia of undetermined significance (AUS) often undergo additional diagnostic analysis with the Afirma Gene Expression Classifier (GEC), which classifies these as either high probability of being benign (GEC-B) or suspicious for malignancy (GEC-S). Our goal was to assess the clinical validity and utility of GEC in the evaluation of AUS cytology and evaluate the performance of ultrasonography (USG) for predicting malignancy in this subset. METHODS: We conducted a study with a retrospective cohort of patients from January 2012 to January 2014 who had FNA of thyroid nodules >1 cm in size with AUS cytology. RESULTS: Cleveland Clinic Florida has an overall prevalence of AUS of 5%. A total of 119 cases with nodules >1 cm in size were reported as AUS. Forty-eight (40.3%) had a GEC performed after the first FNA (AUS-1), and 27 of these were GEC-S. Of those 27, 21 went for surgery and 14 (66.6%) had thyroid cancer on histopathology. The remaining 71 with AUS-1 were sent for a second FNA: 19 nodules were benign and did not undergo further evaluation, while the remaining 52 were reported as AUS for the second consecutive time (AUS-2). AUS-2 samples were sent for GEC. Of these 52 AUS-2, 38 (73.1%) were reported as GEC-S. Thirty-five went for surgery and 32 (91.4%) had confirmed malignancy on histopathology. Positive predictive value (PPV) was 91.4% for AUS-2 and 66.6% for AUS-1. Moreover, AUS-2 nodules that were hypoechoic and solid on USG showed a PPV of 92% for malignancy. CONCLUSION: In our practice, the diagnostic accuracy to predict malignancy with GEC for AUS-1 nodules was poor (PPV, 66.6%). The PPV of GEC testing was markedly higher at 91.4% performed after two consecutive AUS cytologies. AUS-2 nodules that were solid and hypoechoic on USG also had a high probability to be malignant (PPV, 92%). We recommend repeat FNA on AUS-1 nodules rather than proceeding directly to GEC testing. Also, we suggest that among AUS-2 nodules, surgery can be recommended when USG shows solid and hypoechoic features with GEC testing reserved for the remainder. ABBREVIATIONS: AUS = atypia of undetermined significance FNA = fine-needle aspiration GEC = gene expression classifier GEC-B = GEC-benign GEC-S = GEC-suspicious for malignancy NPV = negative predictive value PPV = positive predictive value USG = ultrasonography.

SHOULD FNA BE PERFORMED IN PATIENTS WITH A MULTINODULAR GOITER AND COMPRESSIVE SYMPTOMS?

OBJECTIVE: In this study, we aimed to determine whether preoperative thyroid fine-needle aspiration (FNA) in patients with multinodular goiter (MNG) and compressive symptoms influences the type of thyroid surgery performed, the incidence of recurrent thyroid cancer, or the need for successive surgery. METHODS: We retrospectively reviewed the charts of 431 patients who underwent thyroidectomy at our institution from 2008 to 2011. Patients who presented with compressive symptoms and no prior FNA at initial presentation were included in this study. RESULTS: Eighty patients met the criteria for our study, of which 46 (57.5%) underwent FNA prior to surgery and 34 (42.5%) were referred to surgery without FNA. The prevalence rates of malignancy (>1 cm) on surgical pathology in the FNA and non-FNA groups were 41% (n = 19) and 38% (n = 13), respectively. There was no statistically significant difference between the rate of total/subtotal thyroidectomies (71.7% in FNA vs. 79.4% in non-FNA, P = .31), lobectomies/partial thyroidectomies (28.3% in FNA vs. 20.5% in non-FNA, P = .43), neck lymph node dissections (P = .89) or subsequent surgeries (P = .72) between the 2 groups. CONCLUSION: Our findings show that preoperative FNA in patients with an MNG and compressive symptoms does not influence the type of surgery performed, short-term outcomes, or the need for subsequent surgeries. Further studies are needed to validate the need for preoperative FNA in such patients. ABBREVIATIONS: FNA = fine-needle aspiration MNG = multinodular goiter WHO = World Health Organization.

Adrenocorticotropic hormone stimulation test during high-dose glucocorticoid therapy.

OBJECTIVE: To define the effective time frame of adequate serum cortisol response to the short standard 250-microg adrenocorticotropic hormone stimulation test (ACTH-ST) after initiation of high-dose glucocorticoid therapy in order to assist in the diagnosis of adrenal insufficiency. METHODS: We performed an ACTH-ST at 4 different times in hospitalized patients, who had a documented intact hypothalamic-pituitary-adrenal axis and were receiving high-dose dexamethasone therapy for nonendocrine diseases, to determine the time until the serum cortisol response is compromised. The ACTH-ST was performed at the following time intervals after initiation of dexamethasone therapy - 24, 48, 72, and 96 hours. The outcome measures were cortisol levels measured at 0, 30, and 60 minutes after administration of 250 microg of cosyntropin. RESULTS: Of the overall group of 11 study patients, all those (n = 8) tested within the first 72 hours after initiation of dexamethasone therapy had an adequate response (serum cortisol level at 60 minutes, >or=18 microg/dL). Two of the 3 patients tested at 96 hours after initiation of dexamethasone therapy had a suppressed cortisol response at 60 minutes. At 30 minutes, all cortisol levels except 1 were inadequate (<18 micro/dL). CONCLUSION: This study suggests indirectly that the ACTH-ST may be used for the diagnosis of suspected adrenal insufficiency within the first 3 days after initiation of empiric glucocorticoid therapy. An inadequate response of serum cortisol at 60 minutes to the ACTH-ST may be indicative of adrenal insufficiency in this setting. Additional studies with more patients in each therapy time point are needed to confirm these initial results.

Corticotropin tests for hypothalamic-pituitary- adrenal insufficiency: a metaanalysis.

CONTEXT: The diagnostic value of tests for detecting hypothalamic-pituitary adrenal insufficiency (HPAI) is controversial. OBJECTIVE: Our objective was to compare standard-dose and low-dose corticotropin tests for diagnosing HPAI. DATA SOURCES: We searched the PubMed database from 1966-2006 for studies reporting diagnostic value of standard-dose or low-dose corticotropin tests, with patient-level data obtained from original investigators. STUDY SELECTION: Eligible studies had more than 10 patients. All subjects were evaluated because of suspicion for chronic HPAI, and patient-level data were available. We excluded studies with no accepted reference standard for HPAI (insulin hypoglycemia or metyrapone test) if test subjects were in the intensive care unit or if only normal healthy subjects were used as controls. DATA EXTRACTION: We constructed receiver operator characteristic (ROC) curves using patient-level data from each study and then merged results to create summary ROC curves, adjusting for study size and cortisol assay method. Diagnostic value of tests was measured by calculating area under the ROC curve (AUC) and likelihood ratios. DATA SYNTHESIS: Patient-level data from 13 of 23 studies (57%; 679 subjects) were included in the metaanalysis. The AUC were as follows: low-dose corticotropin test, 0.92 (95% confidence interval 0.89-0.94), and standard-dose corticotropin test, 0.79 (95% confidence interval 0.74-0.84). Among patients with paired data (seven studies, 254 subjects), diagnostic value of low-dose corticotropin test was superior to standard-dose test (AUC 0.94 and 0.85, respectively; P<0.001). CONCLUSIONS: Low-dose corticotropin test was superior to standard-dose test for diagnosing chronic HPAI, although it has technical limitations.