title: Prospective evaluation of the characteristics and incidence of adenoma-associated dural invasion in Cushing disease.
abstract: OBJECTIVE
  Dural invasion by adrenocorticotropic hormone (ACTH)-secreting adenomas is a significant risk factor for incomplete resection and recurrence in Cushing disease (CD). Since ACTH-producing adenomas are often the smallest of the various types of pituitary tumors at the time of resection, examining their invasion provides the best opportunity to identify the precise sites of early dural invasion by pituitary adenomas. To characterize the incidence and anatomical distribution of dural invasion by ACTH-secreting adenomas, the authors prospectively and systematically analyzed features of dural invasion in patients with CD.
  
  
  METHODS
  The authors prospectively studied consecutive patients with CD undergoing the systematic removal of ACTH-secreting adenoma and histological analysis of the anterior sella dura as well as other sites of dural invasion that were evident at surgery. Clinical, imaging, histological, and operative findings were analyzed.
  
  
  RESULTS
  Eighty-seven patients with CD (58 females and 29 males) were included in the study. Overall, dural invasion by an ACTH-positive adenoma was histologically confirmed in 30 patients (34%). Eighteen patients (60% of dural invasion cases, 21% of all patients) had evidence of cavernous sinus wall invasion (4 of these patients also had other contiguous sites of invasion), and 12 patients (40% of dural invasion cases) had invasion of the sella dura excluding the cavernous sinus wall. Eleven patients (13% all patients) had invasion of the routinely procured anterior sella dura specimen. Preoperative MR imaging revealed an adenoma in 64 patients (74%) but accurately predicted dural invasion in only 4 patients (22%) with cavernous sinus invasion and none of the patients with non-cavernous sinus invasion. Adenomas associated with dural invasion (mean ± SD, 10.9 ± 7.8 mm, range 2-37 mm) were significantly larger than those not associated with dural invasion (5.7 ± 2.1 mm, range 2.5-12 mm; p = 0.0006, Mann-Whitney test).
  
  
  CONCLUSIONS
  Dural invasion by ACTH-producing adenomas preferentially occurs laterally into the wall of the cavernous sinus. Preoperative MR imaging infrequently detects dural invasion, including cavernous sinus invasion. Invasion is directly associated with tumor size. To provide a biochemical cure and avoid recurrence after resection, identification and removal of invaded sella dura, including the medial cavernous sinus wall, are necessary.
authors.affiliation: Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-1414, USA. lonserr@ninds.nih.gov
authors.forename: Russell R
authors.initials: RR
authors.lastname: Lonser
authors.forename: Alexander
authors.initials: A
authors.lastname: Ksendzovsky
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Wind
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Vortmeyer
authors.forename: Edward H
authors.initials: EH
authors.lastname: Oldfield
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D000236:Adenoma / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002426:Cavernous Sinus / Q000473:pathology / Q000601:surgery; D002648:Child; D004388:Dura Mater / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D047748:Pituitary ACTH Hypersecretion / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D011300:Preoperative Care; D011446:Prospective Studies; D012658:Sella Turcica / Q000473:pathology / Q000601:surgery; D055815:Young Adult