title: Ber EP4 and epithelial membrane antigen aid distinction of basal cell, squamous cell and basosquamous carcinomas of the skin.
abstract: OBJECTIVE
  Seventy-five skin tumours were studied to investigate the value of immunohistochemistry in differentiating basal cell, squamous cell and basosquamous carcinomas of the skin.
  
  
  RESULTS
  Archived paraffin-embedded tissue samples of basal cell carcinomas (n = 39), squamous cell carcinomas (n = 23) and basosquamous carcinomas (n = 13) were stained immunohistochemically using a panel of antibodies. All of the basal cell carcinomas stained positively for Ber EP4, in contrast to the group of squamous cell carcinomas, that showed no staining. Basosquamous carcinomas all showed at least some areas of Ber EP4 positivity. None of the basal cell carcinomas, but most of the squamous cell carcinomas (22 of 23) expressed epithelial membrane antigen (EMA). Only one of the basosquamous carcinomas expressed EMA positivity focally. CAM 5.2, carcinoembryonic antigen (CEA) and 34betaE12 antibodies lacked specificity in relation to the different tumour types.
  
  
  CONCLUSIONS
  Distinction of basal and squamous cell carcinomas of the skin can be readily achieved with routine immunohistochemistry using Ber EP4 and EMA. Identification of basosquamous carcinoma is also facilitated with this method.
authors.affiliation: Department of Histopathology, Royal Haslar Hospital, Gosport, UK. trevbeer@dsca.gov.uk
authors.forename: T W
authors.initials: TW
authors.lastname: Beer
authors.forename: P
authors.initials: P
authors.lastname: Shepherd
authors.forename: J M
authors.initials: JM
authors.lastname: Theaker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000954:Antigens, Surface / Q000032:analysis*; D015415:Biomarkers; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology*; D002280:Basal Cell Carcinoma / Q000378:metabolism / Q000473:pathology; D002281:Carcinoma, Basosquamous / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*; D000951:Antigens, Neoplasm
chemical_list: D000954:Antigens, Surface; D015415:Biomarkers; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007633:Keratins; D018396:Mucin-1; C400901:CAM 5.2 antigen; C115012:human epithelial antigen-125; D000951:Antigens, Neoplasm