emerin and Adenocarcinoma--Papillary

Decoration of the nuclear membrane by emerin staining enhances detection of nuclear irregularities typical of papillary thyroid carcinoma (PTC). Our study aims to verify whether staining with emerin is a helpful diagnostic marker in fine-needle aspiration (FNA) cytology. We first designed a prospective study on smears, Thin Prep, and cell block specimens to prove the feasibility of the procedure; subsequently, we designed a retrospective study of 78 FNA cell blocks from cases that, after surgery, turned out to be either benign (34 cases) or malignant lesions (44, of which 31 PTC). From each sample, we obtained two slides, one stained with hematoxylin and eosin (H&E) and the other with emerin. In cases classified as Thy3, HBME-1 and galectin 3 (Gal3) stains had also been performed. Two blinded observers made the judgment concerning Thy categories (as proposed by the British Thyroid Association), first on H&E, then on emerin, HBME-1, and Gal3 stained slides. On cytological preparation, emerin staining represents an effective tool for the detection of nuclear irregularities, allowing for the identification of cases of PTC. In Thy3 cases, emerin staining's sensitivity and specificity (64% and 96%) proved higher than HBME-1's (60% and 88%) and Gal3's (61% and 68%). In conclusion, the immunohistochemical definition of the nuclear membrane, as determined by emerin stain, is a useful tool in the cytological diagnosis of thyroid lesions and can help to solve inconclusive cases by highlighting nuclear irregularities typical of PTC.

Topics: Adenocarcinoma, Papillary; Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Biopsy, Fine-Needle; Cytodiagnosis; Female; Humans; Male; Membrane Proteins; Middle Aged; Nuclear Envelope; Nuclear Proteins; Retrospective Studies; Sensitivity and Specificity; Staining and Labeling; Thyroid Neoplasms; Young Adult

Objective appreciation of irregularities of the nuclear shape is a key parameter in the diagnosis of thyroid lesions, since foldings of the nuclear membrane (NM) featuring indentations, grooves and pseudoinclusions characterize papillary thyroid carcinomas (PTC). The aim was to focus on the immunohistochemistry of emerin, a protein of the NM whose decoration best demarcates the nuclear shape.. Immunohistochemistry of the NM with emerin as well as three-dimensional reconstruction of the images (through deconvolution processing) performed on a series of 54 cases (processed following the tissue array procedure) revealed a uniform arrangement of the NM in non-neoplastic lesions (thyroiditis, microfollicular goitre, follicular adenoma) and normal thyroid as well as in follicular carcinoma. In contrast, irregular folding of the membrane and presence of curling and invaginations, eventually leading to the formation of nuclear pseudoinclusions, was observed in PTC cells.. Decoration of the NM represents an original approach to identify PTC nuclear shape, highlights new structural features and might be helpful in the differential diagnosis between so-called nuclear pseudoinclusions and artefactual 'bubbles'.

Topics: Adenocarcinoma, Papillary; Diagnosis, Differential; Fluorescent Antibody Technique; Humans; Image Interpretation, Computer-Assisted; Immunohistochemistry; Membrane Proteins; Nuclear Envelope; Nuclear Proteins; Thyroid Diseases; Thyroid Neoplasms; Tissue Array Analysis