TY - JOUR T1 - Sporadic granular cell tumours lack recurrent mutations in <em>PTPN11, PTEN</em> and other cancer-related genes JF - Journal of Clinical Pathology JO - J Clin Pathol DO - 10.1136/jclinpath-2017-204849 SP - jclinpath-2017-204849 AU - Josiane Alves França AU - Sílvia Ferreira de Sousa AU - Rennan Garcias Moreira AU - Vanessa Fátima Bernardes AU - Letícia Martins Guimarães AU - Jean Nunes Santos AU - Marina Gonçalves Diniz AU - Ricardo Santiago Gomez AU - Carolina Cavalieri Gomes Y1 - 2017/11/02 UR - http://jcp.bmj.com/content/early/2017/11/02/jclinpath-2017-204849.abstract N2 - Granular cell tumour (GCT) is a benign nerve sheath neoplasm of unknown molecular pathogenesis. Although a skeletal muscle cell origin was initially proposed for GCT, its neural origin, derived from Schwann cells, is supported by S-100 immunopositivity.1 There are few molecular studies on oral GCT.2 GCTs have been previously described in patients with LEOPARD and Noonan syndrome with PTPN11 gene mutations,3–6 as well as in a patient with PTEN hamartoma tumour syndrome with PTEN mutation.7 Therefore, we hypothesised that mutations in these genes could be drivers of sporadic GCT pathogenesis.A convenience sample of six formalin-fixed, paraffin-embedded (FFPE) sporadic oral GCT was selected from the archives of the author’s institution. All samples were located at the tongue and occurred in female subjects ranging from 18 to 42 years old (median age 34 years old). The H&amp;E stained slides were analysed by two pathologists (CCG and RSG) to confirm the diagnosis (figure 1A). Tumour-enriched areas were ensured by microdissection and DNA was isolated using QIAamp DNA FFPE Tissue Kit (Qiagen, USA) and quantified by Qubit 3.0 Fluorometer (Life Technologies, USA) before next-generation sequencing (NGS) library preparation. … ER -