Evaluation of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of ultrasound guided thyroid fine needle aspiration (USGFNA) biopsies performed within our endocrinology service.
Cytology and histopathology results were retrospectively analyzed on all patients who underwent USGFNA biopsy in our outpatient endocrinology clinic between 2016 and 2017. USGFNA was performed with a 25 gauge needle attached to a 10 cc syringe with 6 passes. Statistical analysis was based on each nodule, not on each subject. On site microscopic adequacy evaluation was not performed. Cytology results were categorized as malignant, benign, indeterminate, and unsatisfactory. A gene expression classifier test (Afirma®, Veracyte, Inc., South San Francisco, CA) was done for indeterminate nodules and categorized as benign or suspicious. A 2x2 contingency table was generated. Surgical pathology was the gold standard to classify nodules into benign versus malignant. The study was IRB exempt.
450 nodules were biopsied. 68 nodules were from males (15%) and 382 nodules were from females (85%). 233 nodules (52%) were from right and 197 (44%) from left, 20 (4%) were isthmic. 201 biopsies were done on solitary nodules and 141 on 2 nodules, 84 on 3 nodules and 24 on 4 nodules. The maximum diameter of the nodules was 21.2±11.5 mm (mean±SD). USGFNA results showed the following: 3.3% (n=15) malignant, 65.0% (n=293) benign, 11.0% (n=49) indeterminate, 20.7% (n=93) unsatisfactory. 29 gene classifier tests were performed with 15 suspicious and 11 benign results, RNA could not be recovered in the rest (n=3). Gene classifier test was not done on 20 indeterminate nodules. 66 nodules were operated on with a 59% (n=39) benign and 41% (n= 27) malignant pathology. Out of 66 operated nodules, 23 were classified into true positive, 15 into false positive, 4 into false negative and 24 true negative groups. We found that the sensitivity of USGFNA biopsy was 85%, specificity 63%, PPV 61%, NPV 86% and accuracy 71%.
Our unsatisfactory rate was higher compared to American Thyroid Association rates of malignant 2-5%, benign 55-74%, indeterminate 2-25%, unsatisfactory 5-11%. AACE reported the sensitivity of USGFNA as 83% and specificity as 92%. Our sensitivity was similar, but our specificity was lower. Gene classifier analysis for all indeterminate nodules can decrease false positives.
USGFNA is a useful procedure to differentiate benign from malignant nodules, but can probably be improved with onsite adequacy evaluation and universal use of gene classifier tests for all indeterminate cytology results.
Christopher Barnes– Fellow, Division of Endocrinology and Metabolism, Arnot-Ogden Medical Center, Lake Erie College of Osteopathic Medicine, Horseheads, New York
Sablaa Ali– Endocrinologist, Halo Medical Group
Yusef Hazimeh– Endocrinology fellowship program director, LECOM , Arnot Health, Arnot Ogden Health System
Ahmet Can– Program Director and Faculty, Arnot-Ogden Medical Center, Lake Erie School of Osteopathic Medicine, Horseheads, New York
Division of Endocrinology and Metabolism, Arnot-Ogden Medical Center, Lake Erie College of Osteopathic Medicine
Horseheads, New York
Dr. Barnes graduated from Lake Erie College of Osteopathic Medicine in 2014. He completed residency in Internal Medicine at the Arnot Ogden Medical Center and remains there for fellowship in Endocrinology.
Halo Medical Group
Dr. Ali attended the West Virginia School of Osteopathic Medicine. She completed her internal medicine residency at Palmetto General Hospital in Hialeah, FL, followed by endocrinology fellowship at Arnot Ogden Medical Center in Elmira, NY in 2018. She is currently in private practice in Detroit, MI.
Endocrinology fellowship program director, LECOM , Arnot Health
Arnot Ogden Health System
Board certified in endocrinology, diabetes and metabolism. Board certified in geriatric. Former assistant professor of medicine at Albany medical college.
Program Director and Faculty
Arnot-Ogden Medical Center, Lake Erie School of Osteopathic Medicine
Horseheads, New York
Ahmet Selcuk Can, MD went to medical school in Istanbul Faculty of Medicine and graduated in 1989. He did his internship and residency in internal medicine in Cabrini Medical Center affiliated with New York Medical College, in New York City between 1994 and 1996. He completed his Endocrinology Fellowship in Weill Cornell Medicine and Memorial Sloan-Kettering Cancer Center combined program. During his fellowship, he worked in inborn errors of steroid metabolism and published a paper about molecular genetics of 5 alpha reductase deficiency. After fellowship, he worked in various Hospitals and Universities in Turkey. He published about prevalence of the metabolic syndrome and on the sensitivity and specificity of the thyroid fine needle aspiration biopsies. Before joining to Arnot-Ogden Medical Center in Elmira, New York, he worked in a private practice and had affiliations in the Community Medical Center, in Toms River and Ocean Medical Center in Brick, New Jersey and after that worked as a Professor of Medicine in Termal Vocational School in Yalova, Turkey. He has 20 publications in peer-reviewed journals. He serves as the Program Director for Endocrinology, Diabetes and Metabolism Fellowship at Arnot-Ogden Medical Center in Elmira, NY, affiliated with Lake Erie School of Osteopathic Medicine.