title: Clinicopathological Features of Low-Grade Thyroid-like Nasopharyngeal Papillary Adenocarcinoma.
abstract: OBJECTIVE
  Primary low-grade thyroid-like papillary adenocarcinomas are extremely rare neoplasms that generally originate in the nasopharynx. Here, we describe a novel case of a 15-year-old Chinese girl who was diagnosed with low-grade thyroid-like papillary adenocarcinoma, including a brief review of the literature to reveal the clinicopathological features of low-grade thyroid-like nasopharyngeal papillary adenocarcinoma.
  
  
  METHODS
  Immunohistochemistry was used to evaluate the expression of pan-cytokeratin (CKpan), cytokeratin (CK) 7, thyroid transcription factor 1 (TTF-1), vimentin, epithelial membrane antigen (EMA), thyroglobulin, CD15, S100, P40, CK20, CDX-2, glial fibrillary acidic protein (GFAP), and Ki-67. Additionally,in situhybridization investigation was utilized to identify the presence of small Epstein-Barr virus (EBV)-encoded RNA.
  
  
  RESULTS
  Histopathological analysis revealed florid proliferation of papillary structures lined by columnar epithelial cells with fibrovascular cores. Immunohistochemically, the neoplastic cells were positive for CKpan, CK7, TTF-1, vimentin, and EMA, but negative for thyroglobulin, CD15, S100, P40, CK20, CDX-2, and GFAP. The Ki-67-labeling index reached 5% in the most concentrated spot.In situhybridization for EBV was negative.
  
  
  CONCLUSIONS
  Due to the distinct rarity of low-grade thyroid-like papillary adenocarcinomaswith a favorable clinical outcome, a nationwide effort to raise public awareness of this neoplasm is required.
authors.affiliation: Department of Pathology, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China.
authors.forename: Minhua
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Pathology, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China.
authors.forename: Jiangguo
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Pathology, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Yao
authors.affiliation: Department of Pathology, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
mesh_terms: D000231:Adenocarcinoma, Papillary / Q000175:diagnosis* / Q000209:etiology; D000293:Adolescent; D015415:Biomarkers; D001706:Biopsy; D002277:Carcinoma / Q000175:diagnosis* / Q000209:etiology; D004724:Endoscopy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D009300:Nasal Septum / Q000473:pathology; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000209:etiology
chemical_list: D015415:Biomarkers
keywords: Human herpesvirus 4; Nasopharynx; Papillary adenocarcinoma; Thyroid gland; Thyroid nuclear factor 1