title: Distinguishing pseudoepitheliomatous hyperplasia from squamous cell carcinoma in mucosal biopsy specimens from the head and neck.
abstract: BACKGROUND
  The differentiation of pseudoepitheliomatous hyperplasia from invasive squamous cell carcinoma is a difficult and frequently encountered distinction, especially in biopsy specimens from head and neck mucosa. The problem is compounded by inflamed and often poorly oriented tissue sections.
  
  
  OBJECTIVE
  To distinguish pseudoepitheliomatous hyperplasia from invasive squamous cell carcinoma, utilizing a panel of antibodies to various epithelial and stromal elements (p53, matrix metalloproteinase 1, E-cadherin, and collagen IV) that has been shown to be useful in differentiating intestinal adenomas with invasive adenocarcinoma from displaced adenomatous epithelium.
  
  
  METHODS
  Thirty-three archival specimens (16 squamous cell carcinoma [12 with invasion and 4 with microinvasion] and 17 pseudoepitheliomatous hyperplasia) from head and neck mucosal locations were immunostained and examined by the authors.
  
  
  RESULTS
  We found increased nuclear staining of the invasive tumor cells with p53. There was decreased staining within invasive tumor nests with E-cadherin. There was highly significant increased staining within tumor cells and adjacent stroma with matrix metalloproteinase 1 (P < .001). The only antibody in our panel that did not show a reliable staining pattern was collagen IV. It appeared fragmented in benign inflamed and malignant areas and therefore was not useful.
  
  
  CONCLUSIONS
  p53, matrix metalloproteinase 1, and E-cadherin showed significant staining trends independent of inflammation and suboptimal tissue orientation. Although a properly oriented hematoxylin-eosin-stained section was our gold standard, we found this immunoperoxidase panel useful as a diagnostic adjunct in difficult cases.
authors.affiliation: Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Zarovnaya
authors.forename: Candice
authors.initials: C
authors.lastname: Black
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001706:Biopsy; D015820:Cadherins / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D016586:Granular Cell Tumor / Q000175:diagnosis* / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007124:Immunoenzyme Techniques; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology*; D012871:Skin Diseases / Q000175:diagnosis* / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D016159:Tumor Suppressor Protein p53; D020781:Matrix Metalloproteinase 1