Contents

Search

astrocytoma (astrocytic neoplasm)

neoplasm of astrocytes Epidemiology: 1) account for about 80% of adult primary brain tumors 2) diffuse astrocytomas in general are most common in late middle age with the peak incidence of anaplastic astrocytomas occurring in the 6th decade 3) glioblastoma multiforme: peak incidence in 7th decade Pathology: 1) large & heterogenous group of tumors, with wide differences in their clinical incidence, gross & microscopic features, & biological behavior 2) morphological diversity is attributable partly to the various structural forms displayed by developing, mature & reactive astrocytes, & to the propensity of neoplastic cells to accommodate their shape to the persistence of pre-existing structures in the neural parenchyma 3) marked tendency to become more anaplastic with time -> a tumor initially diagnosed as a diffuse astrocytoma frequently proves on later biopsy to be anaplastic astrocytoma or glioblastoma Microscopic pathology: - fibrillary/gemistocytic/protoplasmic astrocytomas: 1) three grades of progressively increasing anaplasia & rapidity of clinical progression: a) diffuse astrocytoma (grade 2) b) anaplastic astrocytoma (grade 3) c) glioblastoma multiforme (grade 4) 2) histologic features associated with higher grade a) hypercellularity b) nuclear & cytoplasmic atypia c) endothelial proliferation* d) mitotic activity e) necrosis* 3) diagnostic criteria for grading (WHO/St. Anne-Mayo): a) cellular atypia b) mitotic activity c) endothelial proliferation d) necrosis One of the above findings is sufficient for grade II Two are sufficient for grade III Three are sufficient for grade IV (glioblastoma) * best indicators of aggressive behavior Genetics: - defects in CAMTA1 associated with oligodendroglioma & astrocytoma - diminished or absent expression of PHF3 - overexpression of TRIM47 - other implicated genes - SLITRK2, SLITRK3, SLITRK4, MMP24, MMP25 Radiology: - magnetic resonance imaging [5] - infiltrating white matter lesion - contrast enhacement suggests higher grade astrocytoma Management: - neurosurgery - whole brain radiation therapy - chemotherapy is controversial [5] - temozolomide Prognosis: - 3-8 years depending grade of astrocytoma

Specific

anaplastic astrocytoma (grade 3) astrocytic neoplasm, WHO grade 1 diffuse astrocytoma (WHO grade 2) glioblastoma multiforme (GBM) or astrocytoma grade IV pilocytic astrocytoma pilomyxoid astrocytoma pleomorphic xanthoastrocytoma (PXA) subependymal giant cell astrocytoma (SEGA)

General

glial neoplasm (glioma)

References

  1. WHO International Histological Classification of Tumors. Histological Typing of Tumours of the Central Nervous System. Kleihues et al. Springer-Verlag 2nd ed. 1993
  2. Pathology of Tumors of the Nervous System. 5th Ed. DS Russell & LJ Rubinstein, Williams & Wilkins, Baltimore, 1989, pg 95
  3. Cotran et al Robbins Pathologic Basis of Disease, W.B. Saunders Co, Philadelphia, PA 1989 pg 1414
  4. Harrison's Online, Chapter 370, McGraw-Hill, 2002
  5. Medical Knowledge Self Assessment Program (MKSAP) 16, American College of Physicians, Philadelphia 2012

Slides & Images

Figures/diagrams/slides/tables related to astrocytoma images related to astrocytoma