Neuroradiologic characteristics of astroblastoma

Abstract

Introduction: Astroblastoma is a rare glial tumor of uncertain origin. Only a few scattered case reports and one small case series have described the radiologic appearance of this uncommon tumor. Many features previously identified are similar to those of other primary malignant brain tumors. We report the largest imaging series to date and further delineate the CT and MRI features of astroblastoma. We identify those features that may be useful in distinguishing astroblastoma from other neoplasms.

Methods: The radiologic images, pathology reports, and clinical information of 12 patients with pathology-confirmed astroblastoma were retrospectively reviewed. CT and MRI findings including location, morphology, signal intensity, and presence and patterns of enhancement were tabulated.

Results: Patients ranged in age from 0 (newborn) to 50 years with a mean of 20 years at the time of initial diagnosis. A striking female preponderance (11:1) was found. All tumors were supratentorial. There were multiple intratumoral cysts in 7 (58%) of the 12 patients. Nine (75%) showed strong rim enhancement and 3 (25%) showed no rim enhancement.

Conclusion: The imaging features of astroblastoma are identified in 12 previously unreported cases. Distinguishing features that can be used to narrow the differential diagnosis with more common primary brain neoplasms reflect a combination of age, anatomic location, and specific imaging findings such as demarcation, heterogeneous tumor enhancement, rim enhancement, and a multicystic "bubbly" appearance. Intraventricular location, intratumoral hemorrhage with a fluid-fluid level, and dural "tails" are less common but important additions to the imaging spectrum.