MR imaging characteristics of protoplasmic astrocytomas

Neuroradiology. 2011 Jun;53(6):405-11. doi: 10.1007/s00234-010-0741-2. Epub 2010 Jul 20.


Introduction: Protoplasmic astrocytomas are a poorly recognized and uncommon subtype of astrocytoma. While usually categorized with other low-grade gliomas, there is literature to suggest that protoplasmic astrocytomas have differences in biology compared to other gliomas in this group. This paper presents the MR imaging characteristics of a series of eight protoplasmic astrocytomas.

Methods: We retrospectively reviewed MR images and histopathology of eight consecutive cases of histologically proven protoplasmic astrocytomas.

Results: Patients ranged from 17 to 51 years of age with a 5:3 male to female ratio. The tumors were located in the frontal or temporal lobes and tended to be large, well defined, and had a very high signal on T2 (close to cerebrospinal fluid). Generally, a large proportion of the tumor showed substantial signal suppression on T2 fluid-attenuated inversion recovery (FLAIR). Six of the eight lesions also demonstrated a partial or complete rim of reduced apparent diffusion coefficient (ADC) around the T2 FLAIR suppressing portion.

Conclusions: The possibility that a primary cerebral neoplasm represents a protoplasmic astrocytoma should be considered in a patient with a large frontal or temporal tumor that has a very high signal on T2 with a large proportion of the tumor showing substantial T2 FLAIR suppression. A further clue is a partial or complete rim of reduced ADC.

MeSH terms

  • Adolescent
  • Adult
  • Astrocytoma / diagnosis*
  • Astrocytoma / pathology*
  • Brain / pathology*
  • Brain Neoplasms / diagnosis*
  • Brain Neoplasms / pathology*
  • Female
  • Frontal Lobe / pathology
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Temporal Lobe / pathology
  • Young Adult