emerin and Carcinoma--Papillary

Papillary thyroid carcinoma (PTC) is diagnosed in both cytological and histological specimens on the basis of distinct nuclear morphology. These features may not be prominent in some PTC variants and may be seen in some benign conditions. It is necessary to differentiate PTC from other neoplastic and nonneoplastic lesions since it affects treatment strategy and patients' fate. Emerin is a type II integral membrane protein of the inner nuclear membrane that has a characteristic staining pattern in PTC. CD56 is a homophilic membrane glycoprotein that is expressed in thyroid follicular epithelial cells and adrenal glands. The aim of this study was to evaluate the diagnostic value of emerin (positivity, percentage, and highlighting nuclear features) and CD56 (positive versus negative) both singly and in combination for differentiation of PTC from other neoplastic and nonneoplastic mimics. This study was performed on 50 cases of PTC, 9 cases of follicular adenoma (FA), and 12 cases of nonneoplastic thyroid lesions using immunohistochemistry for detection of emerin and CD56. Positive emerin expression was seen in 82% of PTC and in 16.7% of nonneoplastic cases with an absence of expression in FA. CD56 was expressed in 88.9% of FA, 91.7% of nonneoplastic cases and in a minority of PTC cases (6%). Positive emerin revealed 82% sensitivity and 90% specificity, while emerin-highlighted nuclear changes was more specific (95%). Negative CD56 expression revealed 84% sensitivity and 90% specificity. Combined positive emerin (including highlighting nuclear changes) and negative CD56 showed 72% sensitivity and 100% specificity. Positive emerin expression (moderate/strong) and its highlighting nuclear changes combined with negative CD56 could be a very helpful procedure in difficult and overlapping cases with high diagnostic validity (high specificity and positive predictive value).

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Carcinoma, Papillary; CD56 Antigen; Child; Female; Humans; Immunohistochemistry; Male; Membrane Proteins; Middle Aged; Nuclear Proteins; Retrospective Studies; Thyroid Cancer, Papillary; Thyroid Neoplasms; Young Adult

Recently, it has been reported that identifying nuclear membrane irregularities with anti-emerin antibody is useful for papillary thyroid carcinoma diagnosis. However, literature regarding the significance of emerin immunohistochemistry in thyroid is limited. We evaluated the diagnostic accuracy of the well-established nuclear alterations, nuclear protrusions and recently described nuclear shapes (garlands and star-like shapes) with emerin immunohistochemistry and hematoxylin- eosin stain in thyroid lesions. We further evaluated the diagnostic accuracy measures of tissue microarrays evaluated with both stains, to detect whether emerin immunohistochemistry improves the diagnostic accuracy for papillary thyroid carcinoma. For papillary thyroid carcinoma, pseudo- inclusions were best performers with emerin (diagnostic accuracy: 0.91), whereas with hematoxylin- eosin diagnostic accuracy of grooves was the highest (0.92). For follicular variant of papillary thyroid carcinoma, with both stains, predominately oval nuclear shape had the best diagnostic performance (diagnostic accuracy: 0.95). Nuclear protrusions were poor identifiers for papillary thyroid carcinoma. However, with emerin immunohistochemistry, they could successfully identify malignancy in 83% of the cases. Using emerin immunohistochemistry, in addition to hematoxylin- eosin improved the diagnostic accuracy for papillary thyroid carcinoma when compared to hematoxylin- eosin evaluation only (sensitivity: 0.70 vs 0.86, negative predictive value: 0.81 vs. 0.94, diagnostic accuracy: 0.87 vs. 0.94). Consistent with the previous literature, our findings indicate that emerin immunohistochemistry may be used as an adjunct diagnostic method to identify papillary thyroid carcinoma. Additionally, we suggest that nuclear protrusions detected with emerin imunohistochemistry may be used as indicators of malignant behavior in small tissue samples of thyroid.

Topics: Adenocarcinoma; Biomarkers, Tumor; Carcinoma; Carcinoma, Papillary; Cell Differentiation; Epithelial Cells; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Membrane Proteins; Nuclear Proteins; Predictive Value of Tests; Retrospective Studies; Sensitivity and Specificity; Thyroid Cancer, Papillary; Thyroid Neoplasms

Immunohistochemical staining (IHC) with emerin, an integral inner nuclear membrane protein, highlights nuclear membrane details in papillary thyroid carcinoma (PTC). We evaluated emerin for highlighting nuclear shape, grooves, inclusions, circumferential nuclear membrane irregularities ("garlands"), deep "stellate" membrane invaginations, and crescents in 34 fine-needle aspiration (FNA) cell blocks, PTC (n = 24) and follicular neoplasms (FN) (n = 10). Tissue microarrays were also examined for 182 cases, PTC (n = 95) and non-PTC (n = 87). Emerin IHC of PTC revealed a predominantly oval nuclear shape in the majority of cases, with FN demonstrating round nuclei and FV of PTC showing a roughly equal distribution of round and oval shapes. In addition to oval nuclear shape, the presence of emerin-positive nuclear grooves, circumferential emerin nuclear "garlands," nuclear crescent shapes, and chromatin clearing on cell block H&E staining were significant predictors of PTC by regression analysis. Emerin IHC of thyroid FNA and surgical specimens serves as a useful adjunct to conventional H&E staining in the diagnosis of PTC and its distinction from FN by delineating diagnostic nuclear membrane irregularities ("garlands" and crescents), nuclear grooves, and a characteristic oval nuclear shape. In diagnostically challenging cases with limited cellularity, emerin staining can help to provide a more definitive diagnosis of PTC.

Topics: Carcinoma, Papillary; Cell Nucleus; Humans; Membrane Proteins; Nuclear Envelope; Nuclear Proteins; Thyroid Neoplasms