Thyroid nodules with benign findings at cytologic examination: Results of long-term follow-up with US

Soo Yeon Kim, Kyung Hwa Han, Hee Jung Moon, jinyoung kwak, Woong Youn Chung, Eunkyung Kim

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Purpose: To investigate the natural history of thyroid nodules found to be benign at initial fine-needle aspiration biopsy (FNAB) to determine the percentage of nodules that increased in volume by more than 50% as being an indicator of malignancy. Materials and Methods: This retrospective observational cohort study was approved by the institutional review board, and the need to obtain informed consent was waived. The study included 854 FNAB-confirmed benign thyroid nodules. Suspicious ultrasonographic (US) features included marked hypoechogenicity, irregular or microlobulated margin, microcalcification, and taller-than-wide shape. Univariate and multivariate generalized linear mixed models were used to assess the association with nodule growth greater than 50% in volume. Results: For the 854 nodules, the initial mean diameter was 19.92 mm (range, 3.10-60.00 mm), and the initial mean volume was 3.19 cm3 (range, 0.01-4.64 cm3). The majority (682 [79.9%] of 854) of thyroid nodules with benign cytologic results at initial FNAB did not grow more than 50% in volume during 4 years of mean follow-up (range, 7-101 months). More than 4 years of follow-up time versus less than 2 years, younger age, a cystic component of less than 25%, and nodule size 1 cm or larger versus less than 1 cm were independently associated with growth. There was only one malignant nodule (0.6%) among 172 thyroid nodules with a volume increase of 50% or greater during the entire follow-up time. Ten malignant nodules (overall malignancy rate: 1.2%) were detected among the 854 total nodules, and eight of these 10 nodules showed suspicious features at US. Conclusion: Repeat FNAB for nodules showing more than 50% growth in volume is unlikely to result in a diagnosis of malignancy. A positive FNAB result for malignancy is significantly more likely in the presence of suspicious US features.

Original languageEnglish
Pages (from-to)272-281
Number of pages10
JournalRadiology
Volume271
Issue number1
DOIs
Publication statusPublished - 2014 Jan 1

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Thyroid Nodule
Fine Needle Biopsy
Neoplasms
Growth
Calcinosis
Research Ethics Committees
Informed Consent
Observational Studies
Linear Models
Cohort Studies

All Science Journal Classification (ASJC) codes

  • Radiology Nuclear Medicine and imaging

Cite this

Kim, Soo Yeon ; Han, Kyung Hwa ; Moon, Hee Jung ; kwak, jinyoung ; Chung, Woong Youn ; Kim, Eunkyung. / Thyroid nodules with benign findings at cytologic examination : Results of long-term follow-up with US. In: Radiology. 2014 ; Vol. 271, No. 1. pp. 272-281.
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title = "Thyroid nodules with benign findings at cytologic examination: Results of long-term follow-up with US",
abstract = "Purpose: To investigate the natural history of thyroid nodules found to be benign at initial fine-needle aspiration biopsy (FNAB) to determine the percentage of nodules that increased in volume by more than 50{\%} as being an indicator of malignancy. Materials and Methods: This retrospective observational cohort study was approved by the institutional review board, and the need to obtain informed consent was waived. The study included 854 FNAB-confirmed benign thyroid nodules. Suspicious ultrasonographic (US) features included marked hypoechogenicity, irregular or microlobulated margin, microcalcification, and taller-than-wide shape. Univariate and multivariate generalized linear mixed models were used to assess the association with nodule growth greater than 50{\%} in volume. Results: For the 854 nodules, the initial mean diameter was 19.92 mm (range, 3.10-60.00 mm), and the initial mean volume was 3.19 cm3 (range, 0.01-4.64 cm3). The majority (682 [79.9{\%}] of 854) of thyroid nodules with benign cytologic results at initial FNAB did not grow more than 50{\%} in volume during 4 years of mean follow-up (range, 7-101 months). More than 4 years of follow-up time versus less than 2 years, younger age, a cystic component of less than 25{\%}, and nodule size 1 cm or larger versus less than 1 cm were independently associated with growth. There was only one malignant nodule (0.6{\%}) among 172 thyroid nodules with a volume increase of 50{\%} or greater during the entire follow-up time. Ten malignant nodules (overall malignancy rate: 1.2{\%}) were detected among the 854 total nodules, and eight of these 10 nodules showed suspicious features at US. Conclusion: Repeat FNAB for nodules showing more than 50{\%} growth in volume is unlikely to result in a diagnosis of malignancy. A positive FNAB result for malignancy is significantly more likely in the presence of suspicious US features.",
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Thyroid nodules with benign findings at cytologic examination : Results of long-term follow-up with US. / Kim, Soo Yeon; Han, Kyung Hwa; Moon, Hee Jung; kwak, jinyoung; Chung, Woong Youn; Kim, Eunkyung.

In: Radiology, Vol. 271, No. 1, 01.01.2014, p. 272-281.

Research output: Contribution to journalArticle

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T1 - Thyroid nodules with benign findings at cytologic examination

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AU - Kim, Soo Yeon

AU - Han, Kyung Hwa

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N2 - Purpose: To investigate the natural history of thyroid nodules found to be benign at initial fine-needle aspiration biopsy (FNAB) to determine the percentage of nodules that increased in volume by more than 50% as being an indicator of malignancy. Materials and Methods: This retrospective observational cohort study was approved by the institutional review board, and the need to obtain informed consent was waived. The study included 854 FNAB-confirmed benign thyroid nodules. Suspicious ultrasonographic (US) features included marked hypoechogenicity, irregular or microlobulated margin, microcalcification, and taller-than-wide shape. Univariate and multivariate generalized linear mixed models were used to assess the association with nodule growth greater than 50% in volume. Results: For the 854 nodules, the initial mean diameter was 19.92 mm (range, 3.10-60.00 mm), and the initial mean volume was 3.19 cm3 (range, 0.01-4.64 cm3). The majority (682 [79.9%] of 854) of thyroid nodules with benign cytologic results at initial FNAB did not grow more than 50% in volume during 4 years of mean follow-up (range, 7-101 months). More than 4 years of follow-up time versus less than 2 years, younger age, a cystic component of less than 25%, and nodule size 1 cm or larger versus less than 1 cm were independently associated with growth. There was only one malignant nodule (0.6%) among 172 thyroid nodules with a volume increase of 50% or greater during the entire follow-up time. Ten malignant nodules (overall malignancy rate: 1.2%) were detected among the 854 total nodules, and eight of these 10 nodules showed suspicious features at US. Conclusion: Repeat FNAB for nodules showing more than 50% growth in volume is unlikely to result in a diagnosis of malignancy. A positive FNAB result for malignancy is significantly more likely in the presence of suspicious US features.

AB - Purpose: To investigate the natural history of thyroid nodules found to be benign at initial fine-needle aspiration biopsy (FNAB) to determine the percentage of nodules that increased in volume by more than 50% as being an indicator of malignancy. Materials and Methods: This retrospective observational cohort study was approved by the institutional review board, and the need to obtain informed consent was waived. The study included 854 FNAB-confirmed benign thyroid nodules. Suspicious ultrasonographic (US) features included marked hypoechogenicity, irregular or microlobulated margin, microcalcification, and taller-than-wide shape. Univariate and multivariate generalized linear mixed models were used to assess the association with nodule growth greater than 50% in volume. Results: For the 854 nodules, the initial mean diameter was 19.92 mm (range, 3.10-60.00 mm), and the initial mean volume was 3.19 cm3 (range, 0.01-4.64 cm3). The majority (682 [79.9%] of 854) of thyroid nodules with benign cytologic results at initial FNAB did not grow more than 50% in volume during 4 years of mean follow-up (range, 7-101 months). More than 4 years of follow-up time versus less than 2 years, younger age, a cystic component of less than 25%, and nodule size 1 cm or larger versus less than 1 cm were independently associated with growth. There was only one malignant nodule (0.6%) among 172 thyroid nodules with a volume increase of 50% or greater during the entire follow-up time. Ten malignant nodules (overall malignancy rate: 1.2%) were detected among the 854 total nodules, and eight of these 10 nodules showed suspicious features at US. Conclusion: Repeat FNAB for nodules showing more than 50% growth in volume is unlikely to result in a diagnosis of malignancy. A positive FNAB result for malignancy is significantly more likely in the presence of suspicious US features.

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