title: Comparative immunohistochemical expression of β-catenin, EGFR, ErbB2, and p63 in adamantinomatous and papillary craniopharyngiomas.
abstract: Craniopharyngiomas (CPs) are rare epithelial tumors located mainly in the sellar/parasellar region. CPs have been classified into histopathologically, genetically, clinically and prognostically two distinctive subtypes: adamantinomatous and papillary variants.
  
  
  OBJECTIVE
  To determine the immunohistochemical expression of β-catenin, EGFR, ErbB2, and p63 in adamantinomatous and papillary CPs.
  
  
  METHODS
  β-Catenin, EGFR, ErbB2, and p63 immunostaining was performed on paraffin embedded tissue sections of 25 CPs including 18 adamantinomatous craniopharyngioma (ACP) and 7 cases of papillary craniopharyngiomas (PCPs).
  
  
  RESULTS
  17 cases (94%) of ACP exhibited strong nuclear/cytoplasmic expression of β-catenin. On the contrary, all cases of PCP showed exclusively membranous expression (P value<0.0001). Regarding EGFR, 15 (83%) and 5 cases (71%) of APC and PCP respectively were positive. On the other hand, only 3 cases (17%) of APC and none of PCP exhibited positivity for ErbB2. p63 over-expression was observed in 16 cases of ACP (89%) and 6 cases of PCP (86%). However, the distribution of p63 staining was diffuse in ACP, while in PCP; the staining was mainly restricted to the basal cell layer.
  
  
  CONCLUSIONS
  Nuclear accumulation of β-catenin is a diagnostic hallmark of the ACP and is very helpful in the differential diagnosis between both ACP and PCP in the setting of small biopsies. Moreover, the restricted nuclear β-catenin accumulation in the cohesive cell clusters within the whorl-like areas supports that aberrant β-catenin expression may play a role in the morphogenesis of ACP.
authors.affiliation: Department of Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt. Electronic address: ghadaesheba@yahoo.com.
authors.forename: Ghada E
authors.initials: GE
authors.lastname: Esheba
authors.affiliation: Department of Pathology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
authors.forename: Amal A
authors.initials: AA
authors.lastname: Hassan
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003397:Craniopharyngioma / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D051176:beta Catenin; C495270:CTNNB1 protein, human; C115051:TP63 protein, human; C512478:EGFR protein, human; C508053:ERBB2 protein, human
keywords: Adamantinomatous craniopharyngioma; Craniopharyngiomas; EGFR; Papillary craniopharyngiomas; p63; β-Catenin