title: An analysis of 2,480 space-occupying lesions of the orbit from 1976 to 2011.
abstract: OBJECTIVE
  To evaluate the frequencies of orbital space-occupying lesions seen at single orbital unit in a period of 35 years.
  
  
  METHODS
  In this retrospective case series, the authors reviewed the medical records of 2,480 consecutive patients referred to the authors' Orbital Unit for evaluation of an orbital mass between 1976 and 2011. The final diagnosis in each case was established by a combination of history, ocular findings, diagnostic imaging, and histopathologic analysis, when available. The number and percentage of benign and malignant tumors were determinated, also according to the age of the patients and the tumor location within the orbit. This study adhered to the principles of the Declaration of Helsinki.
  
  
  RESULTS
  Of the 2,480 lesions, 1,697 (68%) were benign and 783 (32%) were malignant. The most frequent benign tumors were dermoid cyst (14%) and cavernous hemangioma (9%). The most common malignant tumors were non-Hodgkin lymphoma (12%), basal cell carcinoma (3%), and orbital metastases (3%). In patients younger than 60 years, benign tumors are more frequent, whereas in patients older than 60 years, the frequency of malignant tumors increased. Regarding the distribution in the orbit, the most common tumors were dermoid cyst (206 cases) in the upper-outer quadrant, mucocele (155 cases) in the upper-inner quadrant, basal cell epithelioma (35 cases) in the lower-inner quadrant, cavernous hemangioma (68 cases) in the lower-outer quadrant, and meningioma (90 cases) in central space. Most of the tumors were located in the upper-outer quadrant. In the lower-inner quadrant, malignant tumors were more frequent than benign tumors.
  
  
  CONCLUSIONS
  The authors' findings highlight the distinctive nature of the orbital oncology experience at an ocular oncology department.
authors.affiliation: Orbital Unit, Department of Visual Science, University of Naples Federico II, Napoli, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Bonavolontà
authors.forename: Diego
authors.initials: D
authors.lastname: Strianese
authors.forename: Piergiacomo
authors.initials: P
authors.lastname: Grassi
authors.forename: Chiara
authors.initials: C
authors.lastname: Comune
authors.forename: Fausto
authors.initials: F
authors.lastname: Tranfa
authors.forename: Giovanni
authors.initials: G
authors.lastname: Uccello
authors.forename: Adriana
authors.initials: A
authors.lastname: Iuliano
mesh_terms: D000328:Adult; D002280:Basal Cell Carcinoma / Q000453:epidemiology* / Q000473:pathology; D003884:Dermoid Cyst / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006392:Hemangioma, Cavernous / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D009362:Neoplasm Metastasis; D009918:Orbital Neoplasms / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies