title: Retrospective analysis of nonendodontic periapical lesions misdiagnosed as endodontic apical periodontitis lesions in a population of Taiwanese patients.
abstract: OBJECTIVE
  We aimed to evaluate nonendodontic periapical lesions clinically misdiagnosed as endodontic periapical pathoses in a population of Taiwanese patients.
  
  
  METHODS
  Cases (2000-2014) of histopathological diagnoses of nonendodontic periapical lesions were retrieved from all cases with a clinical diagnosis of radicular cyst, apical granuloma, or apical periodontitis in the institution. These cases were regarded as misdiagnosed nonendodontic periapical lesions, of which the types and frequencies, in addition to the demographic data, were determined.
  
  
  RESULTS
  Four thousand and four specimens were clinically diagnosed as endodontically associated pathoses, of which 118 cases (2.95%) received a histopathological diagnosis of a nonendodontic pathologic entity, the most frequent lesion being keratocystic odontogenic tumor (KCOT, n = 38, 32.20%), followed by fibro-osseous lesion (n = 18, 15.25%), and dentigerous cyst (n = 13, 11.02%). Nine malignant lesions in the periapical area [squamous cell carcinoma (n = 7, 5.93%), adenoid cystic carcinoma (n = 1, 0.85%), and Langerhans cell histiocytosis (n = 1, 0.85%)] were also noted.
  
  
  CONCLUSIONS
  A wide variety of histopathological diagnoses, including benign odontogenic and non-odontogenic cystic and tumorous lesions and infectious diseases, as well as malignant lesions, was noted in these 118 cases of nonendodontic periapical lesions. Squamous cell carcinoma was the most predominant malignancy of nonendodontic periapical lesions misdiagnosed as apical periodontitis lesions from imaging examination overlooking the clinical findings.
  
  
  CONCLUSIONS
  The current data form a useful basis for clinicopathological investigation and educational teaching regarding nonendodontic periapical lesions misdiagnosed as endodontic apical periodontitis lesions.
authors.affiliation: Department of Dentistry, Ditmanson Medical Foundation Chia-Yi-Christian Hospital, Chia-Yi, Taiwan.
authors.forename: Hsun-Yu
authors.initials: HY
authors.lastname: Huang
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Oral Pathology & Maxillofacial Radiology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.|Oral & Maxillofacial Imaging Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yuk-Kwan
authors.initials: YK
authors.lastname: Chen
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Oral & Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Edward Cheng-Chuan
authors.initials: EC
authors.lastname: Ko
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Endodontics, Kaohsiung Medical University Hospital, 100 Shih-Chuan 1st Road, Kaohsiung, Taiwan.
authors.forename: Fu-Hsiung
authors.initials: FH
authors.lastname: Chuang
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ping-Ho
authors.initials: PH
authors.lastname: Chen
authors.affiliation: Division of Oral Pathology & Maxillofacial Radiology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Chen
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. k840042@gmail.com.|Division of Oral Pathology & Maxillofacial Radiology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. k840042@gmail.com.|Oral & Maxillofacial Imaging Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. k840042@gmail.com.
authors.forename: Wen-Chen
authors.initials: WC
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010483:Periapical Diseases / Q000175:diagnosis*; D010484:Periapical Granuloma / Q000175:diagnosis; D010485:Periapical Periodontitis / Q000175:diagnosis; D011842:Radicular Cyst / Q000175:diagnosis; D012189:Retrospective Studies; D013624:Taiwan
keywords: Adenoid cystic carcinoma; Ameloblastoma; Endodontic periapical lesions; Nonendodontic periapical lesions; Oral squamous cell carcinoma