Desmoplastic infantile astrocytoma and ganglioglioma
Desmoplastic infantile astrocytoma and gangliogliomas are a rare intracranial tumour, which despite their aggressive appearances tend to have a good prognosis and are considered WHO grade I tumours.
Previously considered separate entities, desmoplastic infantile astrocytoma and desmoplastic infantile ganglioglioma are now grouped together in the current (2016) WHO classification of CNS tumour, recognising the clinical, radiological and pathological similarities of the two entities 2.
The vast majority occur in children below the age of 2 years, and males are more commonly affected with a M:F ratio of approximately 1.5-2:1 1,2. Only a handful of adult cases have been reported, again with a male predilection 2.
A rapidly increasing head circumference is the most common presentation, with symptoms usually presenting in a short time (5 days to 3 months) 1.
Seizure activity is uncommon.
Desmoplastic infantile astrocytoma and gangliogliomas are typically large predominantly cystic tumours with a peripheral solid component abutting and attached to the meninges 2.
These tumours are heterogeneous, with the solid peripheral desmoplastic component composed of meningeal tumour cells, primarily a mixture of fibroblast-like cells and neuroepithelial cells embedded within a connective tissue background 2. In both desmoplastic infantile astrocytomas and desmoplastic infantile gangliogliomas the dominant neuroepithelial component is composed of astrocytes, however, in the latter neoplastic neuronal elements are also identified 2.
Leptomeningeal desmoplastic component:
- GFAP: positive
- neuronal markers (e.g. synaptophysin): positive if ganglion cells present
Desmoplastic infantile ganglioglioma manifests as an exceptionally large cerebral hemispheric mass composed of both cystic and solid portions. The frontal and parietal lobes are the most common sites.
The solid portion of these large masses is typically slightly hyperattenuating and usually located along the cortical margin of the mass. Following administration of contrast, these masses usually enhance intensely and may demonstrate a dural tail 1.
Calcification is variably reported, uncommon in some series and up to 50% in others 1,3.
The solid portions typically have the following signal intensity 1:
- T1: isointense to brain parenchyma
- T2: isointense to brain parenchyma
T1 C+ (Gd)
- intense enhancement
- a dural tail may be seen
Treatment and prognosis
Surgical resection is the treatment of choice, however, because of the large size of these lesions and the firm attachment to the dura, complete resection is difficult and a significant rate of perioperative mortality can result from attempted surgical excision. If complete resection is achieved, however, excellent long-term disease-free survival can be expected 2.
In cases of partial resection, adjunctive chemotherapy may be considered and have been reported to produced some reduction in tumour volume 1.
- 1. Koeller KK, Henry JM. From the archives of the AFIP: superficial gliomas: radiologic-pathologic correlation. Armed Forces Institute of Pathology. Radiographics. 21 (6): 1533-56. Radiographics (full text) - Pubmed citation
- 2. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK "WHO Classification of Tumours of the Central Nervous System. 4th Edition Revised" ISBN: 9789283244929
- 3. Guillaume Trehan, Helene Brugea, Matthieu Vinchob, Chadi Khalil, Marie M. Ruchoux, Patrick Dhellemmes and Gustavo Soto Are. MR Imaging in the Diagnosis of Desmoplastic Infantile Tumor: Retrospective Study of Six Cases. American Journal of Neuroradiology 25:1028-1033, June-July 2004