The study says that researchers have declared that attempts to standardize reporting and cytological criteria for ?ne-needle aspiration of thyroid nodules and was first introduced in 2009, has been updated from The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Although much of the original TBSRTC remains the same, several "enhancements" have been introduced in the 2017 version based on new data and developments in the field. This was published in thyroid.

"All of the refinements of the 2017 Bethesda System, the 2015 American Thyroid Association guidelines, and the upcoming highly anticipated American Association of Clinical Endocrinologists thyroid nodule guidelines and algorithm are attempts to reduce unnecessary thyroid surgery," says R Mack Harrell MD, president of the American College of Endocrinology, who was approached by Medscape Medical News for independent comment.  

"And when surgery is necessary, [the changes are] to make sure that the procedure performed is the most conservative one, and accomplishes the diagnostic and therapeutic goals of the intervention without rendering the patient unnecessarily thyroid hormone dependent," he added.

Major Change Is Accommodation of NIFTP Tumors

Authored by Edmund Cibas, MD, from Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, and Syed Z Ali, MD, from Johns Hopkins Medical Institutions, Baltimore, Maryland, the 2017 update of TBSRTC includes changes to the way malignancy risks are calculated based on new data and developments.

Notably, the new document reinterprets the previous version in one major way, according to Dr Harrell, and that is TBSRTC's careful accommodation of the new noncancer category of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) tumors, which prior to April 2016 were categorized as thyroid cancer. 

"NIFTP tumors have nuclear changes on cytologic evaluation that are identical to other forms of thyroid cancer, but on close long-term clinical follow-up they do not appear to recur or metastasize, and therefore, they do not behave clinically like thyroid cancer," he explained.  NIFTP tumors have atypical findings on cytological evaluation, typically fall into categories 3, 4, or 5, and can only be diagnosed as "not cancer" after a full surgical excision is performed and the entire tumor specimen is examined under a microscope.

And as the ambient rate of thyroid cancer in all thyroid nodules is about 6–8%, "so with the advent of NIFTP, Bethesda 3's diagnostic worth has become more dubious," he explained. Because all NIFTP tumors must be excised to exclude cancer, surgical decision-making has not really changed with Bethesda categories 3, 4, and 5.

However, the number of hemi-thyroidectomies offered has dramatically increased, as removal of the NIFTP tumor lobe is likely curative and thyroid tissue conservation is optimal for patients and endocrine care providers.