Heterogeneous Immunoreactivity of Emerin, a Nuclear Envelope LEM-domain Protein, in Normal Thyroid Follicles

Image analysis of the nuclear characteristics of emerin protein and the correlation with nuclear grooves and intranuclear cytoplasmic inclusions in lung adenocarcinoma

Nuclear size and shape are important components in the diagnosis of pathological specimens. However, a qualitative evaluation is typically applied rather than a quantitative evaluation technique. In the present study, we sought to evaluate the nuclear morphological characteristics of lung adenocarcinoma using whole-slide imaging (WSI) and computer-assisted image analysis (IA). We evaluated the nuclear characteristics of 106 cases of surgically resected lung adenocarcinoma according to Feulgen staining and immunohistochemistry (IHC) for the inner nuclear membrane protein emerin. According to the Feulgen reaction, although the nuclear area (size) of the carcinoma cells was correlated with the nuclear perimeter (NP) (R=0.8973), the nuclear staining intensity of carcinoma cells was not correlated with the nuclear area. Using emerin IHC, we used IA software that was able to detect both the NP and the emerin-stained nuclear membrane length (ENML) in the nucleus, and found that the more nuclei exhibited a longer ENML relative to the NP, the more nuclear grooves and intranuclear cytoplasmic inclusions were present. In addition, the nuclear area was correlated with the percentage of nuclei that had a longer ENML compared to the NP against the total nuclei (R=0.7759). Furthermore, the emerin low expression group showed an enlarged nuclear area (P=0.0264), elongated NP (P=0.0091), and lower shape factor (P=0.0486) compared with the normal emerin expression group. Our data indicated the usefulness of WSI and IA for pathological specimen analysis. In addition, this study is the first to report that the low expression of emerin in cancer cell results in an oval shape of nuclei and nuclear enlargement in clinical samples.

Evaluation of the diagnostic value of emerin and CD56 in papillary thyroid carcinoma - an immunohistochemical study

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).