title: Magnetic resonance imaging findings of intracranial papillary meningioma: a study on eight cases.
abstract: OBJECTIVE
  To increase the awareness on intracranial papillary meningiomas (PMs) by presenting magnetic resonance imaging (MRI) findings on this disease.
  
  
  METHODS
  The MRI findings and clinical presentations of nine discrete lesions in eight patients with pathologically documented PMs were retrospectively analyzed.
  
  
  RESULTS
  Most tumors occurred in young adults. The tumors originated from the convexity meninges in five cases and from the parasagittal regions in four cases. The tumor shape was irregular in six cases, lobulated in two cases, and round in one case. By MRI, nine masses were primarily isointense (n=5) or mildly hypointense (n=4) to gray matter on T1-weighted images and inhomogeneous hyperintense (n=3) or isointense (n=6) to the cortex on T2-weighted and fluid-attenuated inversion recovery images. On diffusion-weighted imaging, the signal intensity of the tumor was increased in all lesions compared with the adjacent parenchyma. Tumor and brain interfaces were unclear in seven cases, cyst formation was observed in eight tumors, scattered hemorrhage was observed in three tumors, signal voids due to vessels were visible in four cases, and eight tumors had moderate or marked irregular peritumoral edema. Enhancement was homogeneous (n=2) or heterogeneous (n=7), an area of focal nodular enhancement was observed in three lesions, and the dural tail sign was visible in seven cases.
  
  
  CONCLUSIONS
  Although PM is rare, it should be considered in the differential diagnosis when evaluating intracranial neoplasms. Younger patient age, as well as imaging features such as unclear tumor-brain interface, internal heterogeneity including cyst formation, irregular enhancement, signal voids of vessels, and marked peritumoral edema can help distinguish PM from typical benign meningiomas.
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xiang-Rong
authors.initials: XR
authors.lastname: Yu
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.lastname: Jun-Zhang
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Bi-Yun
authors.initials: BY
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Wei-Yuan
authors.initials: WY
authors.lastname: Huang
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.lastname: Bo-Yin
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Tan
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Li
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China. Electronic address: gengdaoying2245@126.com.
authors.forename: Dao-Ying
authors.initials: DY
authors.lastname: Geng
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008579:Meningioma / Q000175:diagnosis*; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
keywords: Brain; Magnetic resonance imaging; Meningioma; Papillary variant