title: Temporal bone and sinonasal inverted papilloma: the same pathological entity?
abstract: BACKGROUND
  Inverted papilloma involving the temporal bone is an extremely rare occurrence. Reports in the literature suggest a higher recurrence rate and association with squamous cell carcinoma in Schneiderian-type papillomas of the middle ear than in sinonasal Schneiderian-type papillomas.
  
  
  OBJECTIVE
  To investigate the expression of apoptosis-related proteins, markers of cell proliferation activity, and sex hormone receptors in temporal bone inverted papillomas and to compare this entity with sinonasal papillomas. Design and Subjects We investigated 2 rare cases of inverted papilloma of the temporal bone and a control group of 6 cases of sinonasal inverted papilloma. The expression of p53, Mib-1, p27, and progesterone and estrogen receptors was determined.
  
  
  RESULTS
  In the 2 cases of temporal bone inverted papilloma, p53 expression was 43.75% and 4.92%; p27 expression was higher in temporal bone inverted papilloma (82.45% and 70.53%) than in the sinonasal inverted papilloma group. One of our 2 cases of temporal bone Schneiderian-type papilloma was positive for progesterone receptor.
  
  
  CONCLUSIONS
  The expression of progesterone receptor in 1 of our 2 cases and in the only other case reported in the literature may imply some degree of hormonal dependence of temporal bone inverted papilloma. Our analysis of the expression of apoptosis-related proteins, markers of cell proliferation activity, and sex hormone receptors does not allow us to demonstrate that temporal bone and sinonasal inverted papilloma are different pathological entities.
authors.affiliation: Department of Pathology, Head and Neck Surgery, University of Padua, Padua, Italy. stella.blandamura@unipd.it
authors.forename: Stella
authors.initials: S
authors.lastname: Blandamura
authors.forename: Gino
authors.initials: G
authors.lastname: Marioni
authors.forename: Cosimo
authors.initials: C
authors.lastname: de Filippis
authors.forename: Luciano
authors.initials: L
authors.lastname: Giacomelli
authors.forename: Paola
authors.initials: P
authors.lastname: Segato
authors.forename: Alberto
authors.initials: A
authors.lastname: Staffieri
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity; D009669:Nose Neoplasms / Q000378:metabolism / Q000473:pathology*; D018308:Papilloma, Inverted / Q000378:metabolism / Q000473:pathology*; D011980:Receptors, Progesterone / Q000378:metabolism; D012888:Skull Neoplasms / Q000378:metabolism / Q000473:pathology*; D013701:Temporal Bone; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53