Adult Intramedullary Pilocytic Astrocytomas: Clinical Features, Management, and Outcomes.

[PURPOSE] Adult intramedullary pilocytic astrocytomas (PAs) are exceedingly rare. The aim of this study was to summarize our experiences in treating adult intramedullary PAs.

[MATERIALS AND METHODS] We retrospectively reviewed the records of seven adult patients who underwent microsurgery for intramedullary PAs between 2010 and 2017. Magnetic resonance imaging was the standard radiological investigation. The diagnosis of PAs was based on pathology. All the follow-up data were obtained during office visits.

[RESULTS] There were three males and four females with the mean age of 40.9 years. The tumors generally exhibited hypointensity on T1-weighted images (WI) and hyperintensity on T2WI. Contrast-enhanced T1WI showed heterogeneous enhancement. Gross total resection (GTR) of the tumor was achieved in four cases and subtotal resection (STR) was achieved in three cases. Two cases of STR received postoperative radiotherapy. One STR case had mildly residual tumor regrowth. At the last follow-up, neurological status was improved in six patients.

[CONCLUSION] The accurate diagnosis of adult intramedullary PAs depends on pathology. GTR is the best treatment and the outcome is favorable. STR increases the risk of tumor recurrence, and regular follow-up is necessary. Due to uncertain therapeutic efficacy, radiotherapy should be considered carefully for cases of STR.