Pilomyxoid astrocytoma

As pilomyxoides astrocytoma , a rare is brain tumor called, of a variant of pilocytic astrocytoma is and new to the 2007 WHO classification of tumors of the central nervous system was taken. Since recurrences are not uncommon , the tumor is classified as grade II according to the WHO classification.

Epidemiology and Clinic

Pilomyxoid astrocytomas occur particularly in young children, and less often in older children and adults. The tumors are typically located in the area of the hypothalamus or optic chiasm and are therefore clinically noticeable, among other things, through visual disturbances with visual field defects . In magnetic resonance imaging , pilomyxoid astrocytomas are shown on T1 weighting as hypointense tumors with homogeneous contrast medium uptake.

Neuropathology

Histopathology of pilomyxoid astrocytoma. Hematoxylin-eosin stain , magnification 200x

Histopathologically , the astrocytically differentiated tumor cells form a fine fiber network with a vascular relationship against the background of a myxoid matrix. There is no typical biphasic growth pattern as in pilocytic astrocytomas, Rosenthal fibers or eosinophilic granular bodies are also not characteristic. Mitoses are rare. The proliferative activity can be between 2% and 20%.

Treatment and prognosis

Compared to pilocytic astrocytomas, the biological behavior of pilomyxoid astrocytomas is more aggressive: even after neurosurgical resection of the tumor, local recurrences or the spread of tumor cells in the CSF space can occur.

literature

Scheithauer et al .: Pilocytic Astrocytoma. In: Louis, DD, Ohgaki, H., Wiestler, O., Cavenee, eds. World Health Organization classification of tumors. Pathology and genetics of tumors of the nervous system. Lyon, IARC Press; 2007

Individual evidence

↑ Louis DN, Ohgaki H, Wiestler OD, et al. : The 2007 WHO classification of tumors of the central nervous system . In: Acta Neuropathol. . 114, No. 2, August 2007, pp. 97-109. doi : 10.1007 / s00401-007-0243-4 . PMID 17618441 . PMC 1929165 (free full text).
↑ Tihan T, Fisher PG, Kepner JL, et al. : Pediatric astrocytomas with monomorphous pilomyxoid features and a less favorable outcome . In: J. Neuropathol. Exp. Neurol. . 58, No. 10, October 1999, pp. 1061-8. PMID 10515229 .
↑ Komotar RJ, Burger PC, Carson BS, et al. : Pilocytic and pilomyxoid hypothalamic / chiasmatic astrocytomas . In: Neurosurgery . 54, No. 1, January 2004, pp. 72-9; discussion 79-80. PMID 14683543 .

[1] Louis DN, Ohgaki H, Wiestler OD, et al. : The 2007 WHO classification of tumors of the central nervous system . In: Acta Neuropathol. . 114, No. 2, August 2007, pp. 97-109. doi : 10.1007 / s00401-007-0243-4 . PMID 17618441 . PMC 1929165 (free full text).

[2] Tihan T, Fisher PG, Kepner JL, et al. : Pediatric astrocytomas with monomorphous pilomyxoid features and a less favorable outcome . In: J. Neuropathol. Exp. Neurol. . 58, No. 10, October 1999, pp. 1061-8. PMID 10515229 .

[3] Komotar RJ, Burger PC, Carson BS, et al. : Pilocytic and pilomyxoid hypothalamic / chiasmatic astrocytomas . In: Neurosurgery . 54, No. 1, January 2004, pp. 72-9; discussion 79-80. PMID 14683543 .