title: Immunohistochemical distinction of ocular sebaceous carcinoma from basal cell and squamous cell carcinoma.
abstract: BACKGROUND
  Diagnosis of sebaceous carcinoma of the periorbital region is often delayed. Clinically, this lesion can mimic several inflammatory disorders. Histopathologically, it can mimic either squamous cell or basal cell carcinoma.
  
  
  OBJECTIVE
  To identify an immunohistochemical approach to assist in the diagnosis of periorbital sebaceous carcinoma.
  
  
  METHODS
  The immunohistochemical profiles of several cases of periorbital sebaceous, basal cell, and squamous cell carcinoma were examined.
  
  
  RESULTS
  Although at least focal epithelial membrane antigen (EMA) staining can effectively distinguish sebaceous carcinoma (10 of 11 were positive) from basal cell carcinoma (1 of 16 were positive), most squamous cell carcinomas examined were also focally EMA positive (11 of 14). However, Cam 5.2 reactivity was seen in most sebaceous carcinomas (8 of 11) but no squamous cell carcinomas (0 of 14). In addition, at least focal BRST-1 reactivity was also seen in most sebaceous carcinomas (7 of 11) but no basal cell carcinomas (0 of 16).
  
  
  CONCLUSIONS
  Periorbital sebaceous, basal cell, and squamous cell carcinomas have different immunohistochemical staining profiles; a panel of commonly available antibodies, including anti-EMA, BRST-1, and Cam 5.2, may help distinguish these diseases from each other when that distinction cannot be clearly made by light microscopy alone.
authors.affiliation: Department of Pathology, Yale University School of Medicine, New Haven, Conn 06520-8023, USA. john.sinard@yale.edu
authors.forename: J H
authors.initials: JH
authors.lastname: Sinard
mesh_terms: D018266:Adenocarcinoma, Sebaceous / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002280:Basal Cell Carcinoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D003230:Conjunctival Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005142:Eyelid Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000032:analysis; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis
chemical_list: D000951:Antigens, Neoplasm; C060363:BCA 225 protein, human; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D018396:Mucin-1; D007633:Keratins