title: Acantholytic squamous cell carcinoma is usually associated with hair follicles, not acantholytic actinic keratosis, and is not "high risk": Diagnosis, management, and clinical outcomes in a series of 115 cases.
abstract: BACKGROUND
  Acantholytic squamous cell carcinoma (aSCC) is regarded as a high-risk variant of cutaneous squamous cell carcinoma (SCC). Acantholytic actinic keratosis (aAK) has been regarded as a precursor risk factor for aSCC. However, supporting evidence is limited.
  
  
  OBJECTIVE
  We sought to document clinical features, histologic features, management, and outcomes in a series of aSCC cases.
  
  
  METHODS
  Definitions of aSCC, aAK, and aSCC arising in association with aAK were applied to a consecutive series of aSCC cases. Clinical characteristics and outcomes were obtained from electronic medical records.
  
  
  RESULTS
  Of 115 aSCC cases (103 patients, mean age 71.8 years), actinic keratosis was present in 23% (27/115) but only 7.8% (9/115) exhibited associated aAK. Ten cases (10/115, 9%) fulfilled strict histologic criteria for follicular SCC as previously defined, but 50 of 115 (43%) of our aSCC cases exhibited predominant involvement of follicular epithelium rather than epidermis. Clinical outcome (median follow-up, 36 months) was available in 106 of 115 (92%). One patient experienced regional extension (parotid), and 1 patient experienced a local recurrence (nose). No disease-related metastases or deaths were documented.
  
  
  CONCLUSIONS
  This was a single-institution retrospective study from the United States.
  
  
  CONCLUSIONS
  The presence of acantholysis in cutaneous SCC does not specifically confer aggressive behavior, a finding that may inform clinical practice guidelines.
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, California.
authors.forename: Toru
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, California; Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, California.
authors.forename: Maija
authors.initials: M
authors.lastname: Kiuru
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, California; Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, California.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Konia
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, California; Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, California. Electronic address: maxfung@ucdavis.edu.
authors.forename: Maxwell A
authors.initials: MA
authors.lastname: Fung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D005260:Female; D006201:Hair Diseases / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D018859:Hair Follicle; D006801:Humans; D055623:Keratosis, Actinic / Q000150:complications; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012878:Skin Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D016896:Treatment Outcome
keywords: acantholysis; acantholytic actinic keratosis; cutaneous oncology; dermatopathology; follicular squamous cell carcinoma; nonmelanoma skin cancer; outcomes; prognosis; squamous cell carcinoma