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The Bethesda System revisited: evolution of "atypia of undetermined significance"
S130
Surgical Forum Abstracts
J Am Coll Surg
had an elevated tCa and/or iCa level >6 months after parathyroidectomy. Overall, 16 (4%) patients met criteria for recurrent HPT at 16 months (median; range, 11-121) after initial surgery. Of 8 recurrences iCa elevation predated tCa elevation by 13 months (median; range, 10-15) in 3 patients; 3 had synchronous elevation of tCa and iCa; and 2 had an elevated iCa after known tCa elevation. Elevated tCa at >6 months after parathyroidectomy had the highest sensitivity for predicting recurrent HPT (Table).
Elevated tCa at >6 months Elevated iCa at >6 months Elevated tCa and iCa at >6 months
Sensitivity
Specificity
Positive predictive value
100 62
86 96
24 57
62
99
80
INTRODUCTION: The Bethesda System for Reporting Thyroid Cytopathology was developed in 2007, adding Atypia of Undetermined Significance (AUS) as an additional indeterminate category designed to improve diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB). We examined the evolution of diagnosis, thyroidectomy and malignancy rates within the AUS category post implementation (after the learning curve), and compared to the pre-Bethesda period. METHODS: FNAB results were reviewed from three time periods: pre-Bethesda (January 2000-September 2003), early post-Bethesda (June 2008-November 2009), and late post-Bethesda (December 2009-December 2012). We analyzed rates of diagnosis, operation and malignancy within the AUS category for each time period using Fisher’s exact test (p<0.05 significant).
CONCLUSIONS: As there is no standard definition of recurrent HPT, controversy remains over its true incidence. Using our objective definition, we demonstrate a 4% recurrence rate. Although iCa levels may predate elevation of tCa levels in some patients, this adds little to measurement of tCa alone in detecting recurrence. Therefore, we recommend measurement of only tCa levels in the postoperative follow-up of HPT patients.
RESULTS: FNAB results were reviewed, including 938, 765, and 706 subjects from the pre-Bethesda, early- and late-post Bethesda time periods, respectively. Rate of AUS diagnosis increased over time (12% early vs 17% late, p¼0.003) in the post-Bethesda group. The malignancy rate in this category remained stable preand post-Bethesda. However, the malignancy rate for AUS continues to be higher than originally intended at the system’s inception.
The Bethesda System revisited: evolution of "atypia of undetermined significance" Jacqueline I Lee, MD, Shirley Yan, MD, Fiemu Nwariaku, MD, FACS, Stacey Woodruff, MD, Shelby Holt, MD, FACS, Jennifer Rabaglia, MD, FACS Univeristy of Texas Southwestern Medical Center, Dallas, TX
CONCLUSIONS: The AUS diagnosis rate has increased over time since implementation of the Bethesda system. However, it is not clear whether the inclusion of this category has improved the diagnostic accuracy of thyroid FNAB. In addition, the malignancy rate within AUS lesions remains significantly higher than originally intended, warranting reconsideration of the recommendations for management of these nodules.
Surgical Forum Abstracts
J Am Coll Surg
had an elevated tCa and/or iCa level >6 months after parathyroidectomy. Overall, 16 (4%) patients met criteria for recurrent HPT at 16 months (median; range, 11-121) after initial surgery. Of 8 recurrences iCa elevation predated tCa elevation by 13 months (median; range, 10-15) in 3 patients; 3 had synchronous elevation of tCa and iCa; and 2 had an elevated iCa after known tCa elevation. Elevated tCa at >6 months after parathyroidectomy had the highest sensitivity for predicting recurrent HPT (Table).
Elevated tCa at >6 months Elevated iCa at >6 months Elevated tCa and iCa at >6 months
Sensitivity
Specificity
Positive predictive value
100 62
86 96
24 57
62
99
80
INTRODUCTION: The Bethesda System for Reporting Thyroid Cytopathology was developed in 2007, adding Atypia of Undetermined Significance (AUS) as an additional indeterminate category designed to improve diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB). We examined the evolution of diagnosis, thyroidectomy and malignancy rates within the AUS category post implementation (after the learning curve), and compared to the pre-Bethesda period. METHODS: FNAB results were reviewed from three time periods: pre-Bethesda (January 2000-September 2003), early post-Bethesda (June 2008-November 2009), and late post-Bethesda (December 2009-December 2012). We analyzed rates of diagnosis, operation and malignancy within the AUS category for each time period using Fisher’s exact test (p<0.05 significant).
CONCLUSIONS: As there is no standard definition of recurrent HPT, controversy remains over its true incidence. Using our objective definition, we demonstrate a 4% recurrence rate. Although iCa levels may predate elevation of tCa levels in some patients, this adds little to measurement of tCa alone in detecting recurrence. Therefore, we recommend measurement of only tCa levels in the postoperative follow-up of HPT patients.
RESULTS: FNAB results were reviewed, including 938, 765, and 706 subjects from the pre-Bethesda, early- and late-post Bethesda time periods, respectively. Rate of AUS diagnosis increased over time (12% early vs 17% late, p¼0.003) in the post-Bethesda group. The malignancy rate in this category remained stable preand post-Bethesda. However, the malignancy rate for AUS continues to be higher than originally intended at the system’s inception.
The Bethesda System revisited: evolution of "atypia of undetermined significance" Jacqueline I Lee, MD, Shirley Yan, MD, Fiemu Nwariaku, MD, FACS, Stacey Woodruff, MD, Shelby Holt, MD, FACS, Jennifer Rabaglia, MD, FACS Univeristy of Texas Southwestern Medical Center, Dallas, TX
CONCLUSIONS: The AUS diagnosis rate has increased over time since implementation of the Bethesda system. However, it is not clear whether the inclusion of this category has improved the diagnostic accuracy of thyroid FNAB. In addition, the malignancy rate within AUS lesions remains significantly higher than originally intended, warranting reconsideration of the recommendations for management of these nodules.