J Pathol Transl Med.  2016 Jul;50(4):287-293. 10.4132/jptm.2016.04.04.

Morphometric Analysis of Thyroid Follicular Cells with Atypia of Undetermined Significance

• Kang Y
• Lee YJ
• Jung J
• Lee Y
• Won NH
• Chae YS

• KMID: 2345551
• DOI: http://doi.org/10.4132/jptm.2016.04.04

Abstract

BACKGROUND
Atypia of undetermined significance (AUS) is a category that encompasses a heterogeneous group of thyroid aspiration cytology. It has been reclassified into two subgroups based on the cytomorphologic features: AUS with cytologic atypia and AUS with architectural atypia. The nuclear characteristics of AUS with cytologic atypia need to be clarified by comparing to those observed in Hashimoto thyroiditis and benign follicular lesions.
METHODS
We selected 84 cases of AUS with histologic follow-up, 24 cases of Hashimoto thyroiditis, and 26 cases of benign follicular lesions. We also subcategorized the AUS group according to the follow-up biopsy results into a papillary carcinoma group and a nodular hyperplasia group. The differences in morphometric parameters, including the nuclear areas and perimeters, were compared between these groups.
RESULTS
The AUS group had significantly smaller nuclear areas than the Hashimoto thyroiditis group, but the nuclear perimeters were not statistically different. The AUS group also had significantly smaller nuclear areas than the benign follicular lesion group; however, the AUS group had significantly longer nuclear perimeters. The nuclear areas in the papillary carcinoma group were significantly smaller than those in the nodular hyperplasia group; however, the nuclear perimeters were not statistically different.
CONCLUSIONS
We found the AUS group to be a heterogeneous entity, including histologic follow-up diagnoses of papillary carcinoma and nodular hyperplasia. The AUS group showed significantly greater nuclear irregularities than the other two groups. Utilizing these features, nuclear morphometry could lead to improvements in the accuracy of the subjective diagnoses made with thyroid aspiration cytology.

Keyword

Atypia of undetermined significance; Morphometric analysis; Thyroid

MeSH Terms

Biopsy
Carcinoma, Papillary
Diagnosis
Follow-Up Studies
Hashimoto Disease
Hyperplasia
Thyroid Gland*

Figure

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  Fig. 1. Digital image analysis using ImagePro 6 software. The selected cells are marked in red.

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  Fig. 2. (A, C, E) Cytologic slides for atypia of undetermined significance. Panels B, D, and F are the corresponding histologic findings of panels A, C, and E, respectively. Finally, images are the cytologic slides for Hashimoto thyroiditis (G) and benign follicular nodule (H), respectively. They have no corresponding histologic slides, as a surgical resection was not performed. (B) Papillary carcinoma. (D) Papillary carcinoma (follicular variant). (F) Nodular hyperplasia.

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