title: BRAF mutation positive papillary thyroid carcinoma is less advanced when Hashimoto's thyroiditis lymphocytic infiltration is present.
abstract: BACKGROUND
  Concomitant papillary thyroid cancer (PTC) and Hashimoto's thyroiditis (HT) is a frequent occurrence. Whether these two conditions are linked and whether PTC with concurrent HT has distinct clinicopathological characteristics are still debated issues. Lymphocytic infiltration is abundant in HT and might be relevant in the pathogenesis and progression of PTC. BRAF(V600E) mutation is associated with a more advanced PTC at diagnosis; however, its role in the clinicopathological characteristics of PTC with concurrent HT is unknown.
  
  
  METHODS
  We enrolled 146 patients with histological diagnosis of PTC. Microscopic assessment of histology samples was performed to identify the presence of lymphocytic infiltration. Detection of BRAF(V600E) was performed on cytology samples by both direct sequencing and pyrosequencing, and results were correlated with clinical parameters.
  
  
  RESULTS
  Concurrent HT lymphocytic infiltration was associated with the female gender, smaller tumour size, a less frequent extracapsular extension and a lower grade of TNM staging. BRAF(V600E) was more frequent in PTC with concomitant lymphocytic infiltration. In PTC harbouring BRAF(V600E) , concurrent lymphocytic infiltration was still associated with the female gender, a less frequent extracapsular extension and a lower TNM staging.
  
  
  CONCLUSIONS
  These results suggest that lymphocytic infiltration of HT is a protective factor against PTC progression, and it is independent of BRAF mutational status.
authors.affiliation: Department of Clinical Medicine and Surgery, University "Federico II", Naples, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Marotta
authors.forename: Anna
authors.initials: A
authors.lastname: Guerra
authors.forename: Maria C
authors.initials: MC
authors.lastname: Zatelli
authors.forename: Ettore Degli
authors.initials: ED
authors.lastname: Uberti
authors.forename: Vincenza
authors.initials: V
authors.lastname: Di Stasi
authors.forename: Antongiulio
authors.initials: A
authors.lastname: Faggiano
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.forename: Mario
authors.initials: M
authors.lastname: Vitale
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000235:genetics*; D002291:Carcinoma, Papillary / Q000235:genetics*; D005260:Female; D050031:Hashimoto Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics*
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf