Pathological Findings of a Subependymal Giant Cell Astrocytoma Following Treatment With Rapamycin.

Abstract

BACKGROUND:

Tuberous sclerosis complex is a heritable multisystem disorder associated with genes involved in the formation of a tumor-suppressor complex acting through the Ras homologue enriched in brain protein to limit activation of the mammalian target of rapamycin complex I. Mutations in these genes result in enhanced mammalian target of rapamycin signaling and may cause neurological manifestations including brain tubers, subependymal nodules, and subependymal giant cell astrocytomas. These astrocytomas are tumors that arise near the foramen of Monro and may lead to obstructive hydrocephalus. Standard therapy has been surgical resection. More recently, mammalian target of rapamycin inhibitor, everolimus, has been approved for treatment after demonstration of efficacy in prospective clinical trials.

METHODS:

We report a 15 year-old girl with tuberous sclerosis complex who proceeded to surgical resection of her subependymal giant cell astrocytoma after 3 months of treatment with mammalian target of rapamycin inhibition. We compared her subependymal giant cell astrocytoma tissue specimen with 12 untreated subependymal giant cell astrocytomas accessed from The Hospital for Sick Children in Toronto, Canada.

RESULTS:

This girl's histopathological findings were consistent with subependymal giant cell astrocytomas with no exposure to mammalian target of rapamycin inhibitors. There were no major differences identified on immunohistochemistry at targets downstream of mammalian target of rapamycin complex 1 or in neighboring signaling pathways. The majority of cells were reactive to glial fibrillary acidic protein, mitogen-activated protein kinase, phospho-S6, caspase 3 (95% positivity), and NP-1.

CONCLUSION:

In this one individual, rapamycin therapy did not change the histopathological characteristics of subependymal giant cell astrocytoma. Mammalian target of rapamycin inhibition involves complex signaling pathways inducing subependymal giant cell astrocytoma shrinkage. However, its effect is not easily characterized within tumor tissue.

• Authors: Sylvia Cheng, Cynthia Hawkins, Michael D Taylor, Ute Bartels
• Journal: Pediatric neurology (Pediatr Neurol) Vol. 53 Issue 3 Pg. 238-242.e1 (Sep 2015) ISSN: 1873-5150 [Electronic] United States
• PMID: 26173783 (Publication Type: Case Reports, Journal Article)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• Antibiotics, Antineoplastic
• Tuberous Sclerosis Complex 2 Protein
• Tumor Suppressor Proteins
• Sirolimus

Topics

• Adolescent
• Antibiotics, Antineoplastic (therapeutic use)
• Astrocytoma (drug therapy, metabolism, pathology, surgery)
• Female
• Humans
• Immunohistochemistry
• Magnetic Resonance Imaging
• Mutation
• Sirolimus (therapeutic use)
• Tuberous Sclerosis (drug therapy, metabolism, pathology, surgery)
• Tuberous Sclerosis Complex 2 Protein
• Tumor Suppressor Proteins (genetics)