Concurrent solitary fibrous tumor and low-grade fibrillary astrocytoma of the cerebellum

Objective: We report the clinicopathologic features of a solitary fibrous tumor (SFT) having undergonemalignant transformation and being intimately associated with a WHO Grade II astrocytoma. Clinical presentation: A 7-month old patient presented with delayed motor development and hydrocephalus. Intervention: Histologic and immunocytologic methods were applied in the study of the tumors. Resection was initially employed and the SIOP protocol employing vincristine and carboplatin was applied upon tumor recurrence. Conclusion: The biologic basis for the association of SFT and astrocytoma is unknown. The complex lesion differs substantially from WHO Grade IV gliosarcoma and from gliofibroma, lesions in which the disparate elements are linked by metaplasia. Indeed, it may represent a collision tumor. Lastly, induction of the glioma by the solitary fibrous tumor, a mechanism invoked to explain the poorly understood "sarcoglioma," deserves consideration.