title: Bronchogenic cancer: It still exists.
abstract: OBJECTIVE
  Branchial cleft cysts rank among the most common differential diagnoses of cystic cervical masses. Rarely, classic cystic structures exhibit a squamous cell carcinoma differentiation that represents a bronchogenic carcinoma. The existence of bronchogenic carcinoma is controversial due to the lack of systematic immunohistologic workup. The present study aimed to identify the clinical and immunohistologic features of bronchogenic carcinoma to clearly distinguish this entity from other cystic cervical masses.
  
  
  METHODS
  Immunohistologic (epidermal growth factor receptor; cytokeratin 5, 6, 7, 13; and p16) and epidemiologic assessments were performed for branchial cleft cysts (n = 63), bronchogenic carcinomas (n = 5), cystic metastasized oropharyngeal carcinomas (n = 97), and carcinomas of unknown primary (n = 51). The study was conducted as a retrospective case series study with comparison.
  
  
  RESULTS
  The patients with bronchogenic carcinomas differed significantly in age and in the number of involved lymph nodes compared with the cystic metastasized oropharyngeal carcinoma (and carcinoma of unknown primary) patients. Regular histologic wall structures were only observed in the bronchogenic carcinomas and branchial cleft cysts. Solitary cytokeratin-7 staining was only observed in the bronchogenic carcinomas, and all of the bronchogenic carcinomas were p16 negative.
  
  
  CONCLUSIONS
  The existence of bronchogenic carcinoma seems to be plausible based on clinical findings. Cytokeratin-7 and p16 staining might be helpful in the diagnostic workflow.
  
  
  METHODS
  4 Laryngoscope, 126:638-642, 2016.
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Technical University of Munich, Munich, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Strassen
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Technical University of Munich, Munich, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hofauer
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Technical University of Munich, Munich, Germany.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Matsuba
authors.affiliation: Institute of Pathology, Technical University of Munich, Munich, Germany.
authors.forename: Karen
authors.initials: K
authors.lastname: Becker
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Technical University of Munich, Munich, Germany.
authors.forename: Naglaa
authors.initials: N
authors.lastname: Mansour
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Technical University of Munich, Munich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Knopf
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001707:Biopsy, Needle; D001935:Branchioma / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D002283:Carcinoma, Bronchogenic / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D055815:Young Adult
keywords: Bronchogenic cancer; branchial cleft cyst; carcinoma of unknown primary; head and neck squamous cell carcinomas; lymph node metastasis