pilocytic astrocytoma


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Related to pilocytic astrocytoma: medulloblastoma

pilocytic as·tro·cy·to·ma

a slowly growing astrocytoma composed histologically of elongated astrocytes; often located in the optic chiasm region of the third ventricle, hypothalamus, or cerebellum, predominantly in younger people.
Synonym(s): piloid astrocytoma

pi·lo·cyt·ic as·tro·cy·to·ma

(pī'lō-sit'ik as'trō-sī-tō'mă)
A slowly growing astrocytoma composed histologically of elongated astrocytes; often located in the optic chiasm region of the third ventricle, hypothalamus, or cerebellum, predominantly in younger individuals.

pilocytic astrocytoma

A low-grade (relatively slow growing) tumor made of supporting cells of the brain. It usually found in the cerebellum of children, in whom it causes symptoms of headache, nausea, vomiting, and difficulty with balance.
See also: astrocytoma
References in periodicals archive ?
Pilocytic astrocytomas are relatively well circumscribed; however, the higher-grade astrocytomas demonstrate poorly defined margins (Figure 4).
Earlier research showed that most sporadic pilocytic astrocytomas possess an abnormal form of a signaling protein known as BRAF.
Quality of life (QOL) assessments in children with juvenile pilocytic astrocytomas (JPA) have shown that overall these children fare better than those with medulloblastoma or ependymoma or than those who receive chemotherapy, radiation therapy, or both.
Oncogenic RAF1 rearrangement and a novel BRAF mutation as alternatives to KIAA1549:BRAF fusion in activating the MAPK pathway in pilocytic astrocytoma.
The two most common diagnostic errors surrounding pineal cyst are pilocytic astrocytoma and pineocytoma.
11,98,99) The glial component in these tumors varies but often resembles either a pilocytic astrocytoma or an infiltrating glioma with astrocytic or oligodendroglial features.
The first is a cytologically bland and generally paucicellular astroglial proliferation with spindle, stellate, and piloid cells resembling pilocytic astrocytoma (Figure 12).
Low-grade neoplasms, such as meningioma and pilocytic astrocytoma, may also exhibit this type of spread, but at a slower rate of growth than most malignant tumors.
One case each of pigmented ganglioglioma,16 pilocytic astrocytoma,[17] and pleomorphic xanthoastrocytoma[18] have been reported to date.
1-5] The most recent World Health Organization (WHO) classification (1993) separates astrocytic tumors into 2 main groups: the diffuse astrocytomas (WHO grades 2-4) and "other astrocytomas," the latter comprising a number of fairly distinct clinicopathologic entities, of which pilocytic astrocytoma is by far the most common.
Although the morphologic features were consistent with pituicytoma, the differential diagnosis of a low-grade spindle cell lesion of the sella includes meningioma, schwannoma, spindle cell adenoma, and pilocytic astrocytoma.