title: Natural course of incidentally found nonfunctioning pituitary adenoma, with special reference to pituitary apoplexy during follow-up examination.
abstract: OBJECTIVE
  The increase in the incidental detection of asymptomatic pituitary adenomas, known as "pituitary incidentalomas," led the authors to conduct a survey of the natural course of these lesions.
  
  
  METHODS
  Forty-two patients with clinically nonfunctioning pituitary adenomas who had manifested no neurological or endocrinological disorders were monitored with magnetic resonance imaging studies. The follow-up period ranged from 10.8 to 168.2 months (mean +/- standard deviation, 61.9 +/- 38.2 months). The mean initial tumor size was 18.3 +/- 7 mm. In 21 patients, the tumor increased by at least 10% of its measured size on detection. This increase was first detected between 8.4 and 58.8 months (mean 31.8 +/- 17.6 months) after diagnosis. There was no correlation between the original tumor size, patient age, or the presence of intratumoral cysts and tumor growth. Symptoms were noted in 10 patients during follow up; in four, extensive tumor necrosis accompanied hemorrhage, leading to severe headache, acute ophthalmological symptoms, and panhypopituitarism, which was indicative of pituitary apoplexy. Transsphenoidal surgery was performed in 12 patients with enlarged tumors, including three with apoplexy. With the exception of one apoplectic patient, visual function was recovered in all who underwent surgery. All apoplectic patients continue to manifest hypopituitarism.
  
  
  CONCLUSIONS
  In the course of 4 years, the size of the incidentalomas increased in 40% of 42 patients and became symptomatic in 20%. During the 5-year follow up, pituitary apoplexy developed in 9.5%. These findings may justify early intervention, especially in young individuals with incidentally found macroadenoma.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan. karita@m2.kagoshima-u.ac.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Arita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tominaga
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Kuniki
authors.initials: K
authors.lastname: Eguchi
authors.forename: Koji
authors.initials: K
authors.lastname: Iida
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sumida
authors.forename: Keisuke
authors.initials: K
authors.lastname: Migita
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
mesh_terms: D000236:Adenoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007018:Hypopituitarism / Q000453:epidemiology; D015994:Incidence; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D010899:Pituitary Apoplexy / Q000453:epidemiology*; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000601:surgery; D012307:Risk Factors; D014786:Vision Disorders / Q000453:epidemiology