User:DerekvG/sandbox/braintumor/SGCA

subependymal giant-cell astrocytoma (SGCA)

Subependymal giant cell astrocytomas (SGCAs) are a group of benign (WHO grade I) astrocytomas and are seen with increased incidence in tuberous sclerosis (TS).

SGCA's are a well known manifestation of TS and affects 5 - 15% of patients with the condition.

Location

The foramen of Monroe is the classic location. Some of the subependymal nodules themselves can transform into SGCA over a period of time. Demographics and clinical presentation

They principally affect patients under 20, but are occasionally found in older people. Symptoms are usually a result of obstructive hydrocephalus because of mass effect around the ventricular system, commonly the interventricular foramen (of Monro), the cerebral aqueduct (of Sylvius) or the third or fourth ventricles.

Young children who have tuberous sclerosis may be offered screening becuase of the increased risk of developing subependymal giant cell astrocytomas Radiographic features CT

Typically appears as an intraventricular mass near the foramen of Monro. Iso attenuating to slightly hypoattenuating to grey matter. Calcification is common and haemorrhage is possible. Often shows marked contrast enhancement (differentiating feature from sub ependymal nodule) MRI

   * T1 : heterogenous and hypo to iso intense to grey matter 
   * T2 : heterogenous and hyper intense to grey matter ; calcific components can be hypo intense
   * C+ (GAD) : shows marked enhancement

Treatment

The main treatment is surgical removal and is usually curative. Oral rapamycin (sirolimus) has also been trialled 3. Differential diagnoses

   * central neurocytoma
   * choroid plexus papilloma (CPP)
   * choroid plexus carcinoma

See also

Differential for intraventricular tumours

A 17-year-follow-up case of subependymal giant cell astrocytoma(SGCA) is reported. In 1979, when aged 28 years, the patient first presented obstructive hydrocephalus caused by a tumor in the right lateral ventricle close to the foramen of Monro. It was partially removed by a transcallosal approach. Pathological examinations showed gemistocytic astrocytoma or SGCA associated with tuberous sclerosis. A ventriculoperitoneal shunt was carried out and 36Gy of radiation therapy was administered. Eight months later, the patient suffered from an intraventricular hemorrhage originating from SGCA, but he responded to conservative therapy. He was followed-up by CT scans over 17 years. In 1996, because of rapid regrowth of the tumor, total removal was performed by a transcortical approach via the right frontal horn. The pathological diagnosis was SGCA. The greater part of the recurrent tumor was composed of blood vessels. The tumor cells were grouped into two morphological types, large cells and spindle cells. We compared the tumor in 1996 with that in 1979, each revealing immunohistochemical stainability for glial fibrillary acidic protein(GFAP), neuron specific enolase(NSE) and S-100 protein(S-100). The large cells in 1979 were negative for GFAP, NSE and S-100, but were positive for NSE and S-100 in 1996. The spindle cells in 1979 were positive for GFAP, NSE and S-100, but were negative for GFAP in 1996. The pathological origin of SGCA remains a subject of controversy. These results suggest that the origin of SGCA could be variably differentiated cells like the germinal matrix cells.