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Solid cell nests of the thyroid gland: morphological, immunohistochemical and genetic features
Author(s) -
Manzoni Marco,
Roversi Gaia,
Di Bella Camillo,
Pincelli Angela I,
Cimino Vincenzo,
Perotti Mario,
Garancini Mattia,
Pagni Fabio
Publication year - 2016
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12858
Subject(s) - pax8 , immunohistochemistry , thyroid , pathology , cytokeratin , medicine , differential diagnosis , biology , cancer research , gene , transcription factor , genetics
Aims The correct identification of solid cell nests ( SCN s) is an important issue in thyroid pathology because of the spectrum of differential diagnoses of this type of lesion. Methods and results Ten cases of 295 consecutive thyroidectomies showed the presence of SCN s at histological examination. The identification of the exact SCN type required the distinction of the cystic and solid pattern; SCN s were usually composed of a mixture of main cells ( MC s) and C‐cells ( CC s). The immunohistochemical calcitonin stain identified CC s easily, both inside SCN s and dispersed in islets at the periphery. For the characterization of MC s, we added the utility of p40 to p63. The use of thyroid transcription factor‐1 ( TTF ‐1) helped in their identification, as MC s did not react with this marker; the combination of TTF ‐1 and p40 or p63 IHC stains was useful for the characterization of cystic SCN s of both types 3 and 4. The negativity of mouse monoclonal mesothelioma antibody ( HMBE ‐1) and a very low proliferative index ( MIB ‐1) supported the diagnosis. [Correction added on 23 November 2015, after online publication: MIB ‐1 was incorrectly defined, the expanded form was deleted.] We discourage the use of galectin‐3 (Gal‐3) and cytokeratin‐19 ( CK ‐19), as they have an important overlap with papillary thyroid carcinoma. The complete absence of any B‐Raf proto‐oncogene, serine/threonine kinase ( BRAF ) mutations is an additional fundamental finding. Conclusions We reviewed the most relevant morphological and immunohistochemical features of SCN s and have provided a genetic analysis of the BRAF gene because of its expanding use in thyroid pathology.