Additional Surgery for Occult Risk Factors After Lobectomy in Solitary Thyroid Nodules is Predicted by Cytopathology Classification and Tumor Size.

Abstract

OBJECTIVE:

Clinical practice for differentiated thyroid cancer is moving towards lobectomy rather than total thyroidectomy in patients at low risk of recurrence. However, recurrence risk assessment depends on post-operative findings, while the surgical decision is based on preoperative factors. We determined the preoperative predictors of occult higher-risk pathology and rates of completion thyroidectomy among surgical candidates with nonbenign thyroid nodules 10 to 40 mm and no evidence of extrathyroidal extension or metastasis on preoperative evaluation.

METHODS:

Thyroid surgery cases at a single institution from 2005-2015 were reviewed to identify those meeting American Thyroid Association (ATA) criteria for lobectomy. ATA-based risk stratification from postoperative surgical pathology was compared to preoperative cytopathology, ultrasound, and clinical findings.

RESULTS:

Of 1,995 thyroid surgeries performed for nonbenign thyroid nodules 10 to 40 mm, 349 met ATA criteria for lobectomy. Occult high-risk features such as tall cell variant, gross extrathyroidal invasion, or vascular invasion were found in 36 cases (10.7%), while intraoperative lymphadenopathy led to surgical upstaging in 13 (3.7%). Intermediate risk features such as moderate lymphadenopathy or minimal extrathyroidal extension were present in an additional 44 cases. Occult risk features were present twice as often in Bethesda class 6 cases (35%) as in lower categories (12 to 17%). In multivariable analysis, Bethesda class and nodule size, but not age, race, sex, or ultrasound features, were significant predictors of occult higher-risk pathology.

CONCLUSION:

Most solitary thyroid nodules less than 4 cm and with cytology findings including atypia of undetermined significance through suspicious for papillary thyroid cancer would be sufficiently treated by lobectomy.

ABBREVIATIONS:

ATA = American Thyroid Association; CND = central neck dissection; DTC = differentiated thyroid cancer; ETE = extrathyroidal extension; FNA = fine needle aspiration; FTC/HCC = follicular thyroid carcinoma/Hurthle cell carcinoma; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features; OR = odds ratio; PTC = papillary thyroid cancer; US = ultrasound.

• Authors: Andrew Flagg, Lisa Rooper, Sheila Sheth, Mohammad Shaear, Prasanna Santhanam, Jason Prescott, Matt T Olson, Justin A Bishop, Jennifer S Mammen
• Journal: Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists (Endocr Pract) Vol. 26 Issue 7 Pg. 754-760 (Jul 2020) ISSN: 1530-891X [Print] United States
• PMID: 33471644 (Publication Type: Journal Article)
• Copyright: © 2020 American Association of Clinical Endocrinologists. Published by Elsevier, Inc. All rights reserved.

Topics

• Adenocarcinoma, Follicular
• Carcinoma, Hepatocellular
• Humans
• Liver Neoplasms
• Neoplasm Recurrence, Local
• Retrospective Studies
• Risk Factors
• Thyroid Neoplasms (surgery)
• Thyroid Nodule (surgery)