title: Spontaneous regression together with increased calcification of incidental meningioma.
abstract: BACKGROUND
  Regression of meningioma has been reported after hemorrhage or hormonal withdrawal. However, meningioma regression is rarely observed spontaneously.
  
  
  METHODS
  A right falx meningioma was incidentally diagnosed and was followed at every one-year by magnetic resonance imaging (MRI) for over 7 years. The tumor, with a maximum diameter of 4 cm, showed a slightly high density and was enhanced on computed tomography (CT), and a high intensity with a low-intensity core on T2 MRI, with significant edema. The meningioma gradually shrank together with a decrease of edema and increase of calcification. The initial volume, 25.5 cm(3), regressed linearly to less than half, 9.9 cm(3).
  
  
  CONCLUSIONS
  Here, we report a case of an incidentally diagnosed meningioma that regressed spontaneously. The pattern of the regression was similar to that following gamma knife radiosurgery.
authors.affiliation: Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Hirota
authors.affiliation: Tokyo Women's Medical University Institute for Integrated Medical Sciences, 8-1 Kawada-cho, Shinjyuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Tokyo Women's Medical University Institute for Integrated Medical Sciences, 8-1 Kawada-cho, Shinjyuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Akagawa
authors.affiliation: Kofu Neurosurgery Hospital, 1-16-18 Sakaori, Kofu, Yamanashi, 400-0805, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Onda
authors.affiliation: Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kasuya
keywords: Calcification; incidental; meningioma; regression