All are true about microscopic appearance of pilocytic astrocytoma, EXCEPT:

Pilocytic astrocytomas (grade I/IV) are distinguished from the other types by their pathologic appearance and relatively benign behavior On macroscopic examination, a pilocytic astrocytoma is often cystic; if solid, it may be well circumscribed or, less frequently, infiltrative. On microscopic examination the tumor is composed of bipolar cells with long, thin "hairlike" processes that are GFAP-positive and form dense fibrillary meshworks; Rosenthal fibers and eosinophilic granular bodies, are often present. An increase in the number of blood vessels, often with thickened walls or vascular cell proliferation, is seen but does not imply an unorable prognosis; necrosis and mitoses are uncommon. Ref: Robbins 8th edition Chapter 28.