title: Sphenoid sinus anatomy and suprasellar extension of pituitary tumors.
abstract: OBJECTIVE
  As tumors enlarge, they generally grow along paths of least resistance. For pituitary macroadenomas, extrasellar extension into the suprasellar region, cavernous sinus, or sphenoid sinus may occur. The sphenoid sinus is known to have a variable anatomical configuration, and the authors hypothesize that certain anatomical factors may resist tumor expansion into the sphenoid sinus, thereby directing tumor growth into the suprasellar space. In this paper the authors' goal was to determine if sphenoid anatomy influences pituitary tumor growth.
  
  
  METHODS
  The authors conducted a retrospective analysis of 106 consecutive surgical cases of pituitary macroadenoma. Patient demographics, suprasellar extension, sellar width, and features of the sphenoid intersinus septum were recorded on radiographic review. The chi-square test, t-test, logistic regression, and classification and regression tree analysis were used for statistical analysis.
  
  
  RESULTS
  Of the 106 patients included in the study, 71 (67%) demonstrated suprasellar extension of their tumor. Patients with suprasellar tumor extension had significantly greater intersinus septum width (width > 1.27 mm: OR = 14.32; p = 0.0012) and were significantly older (age > 54 yrs: OR = 3.33; p = 0.0176). They also tended to be male and to have two or more sphenoid partitions (OR = 6.58; p = 0.0306). While patients with suprasellar extension tended to be more likely to have a midline partition and a larger sellar width than their counterparts, these differences did not reach statistical significance.
  
  
  CONCLUSIONS
  Certain aspects of the sphenoid sinus anatomy may function to resist pituitary tumor growth into the sphenoid sinus. Progressive enlargement of pituitary macroadenomas may extend in a suprasellar direction, in part, as a consequence of the sphenoid sinus anatomy.
authors.affiliation: Department of Otolaryngology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA. vijay.ramakrishnan@ucdenver.edu
authors.forename: Vijay R
authors.initials: VR
authors.lastname: Ramakrishnan
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Suh
authors.forename: Jennifer Y
authors.initials: JY
authors.lastname: Lee
authors.forename: Bert W
authors.initials: BW
authors.lastname: O'Malley
authors.forename: M Sean
authors.initials: MS
authors.lastname: Grady
authors.forename: James N
authors.initials: JN
authors.lastname: Palmer
mesh_terms: D000236:Adenoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000601:surgery; D011859:Radiography; D012189:Retrospective Studies; D012658:Sella Turcica / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology*; D012737:Sex Factors; D013101:Sphenoid Sinus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000473:pathology*