Desmoplastic infantile ganglioglioma

Ultrasound, CT and MR imaging demonstrated a large cyst-like superficial lesion in the right parietal lobe, with a small solid marginal component, which was intensely enhanced after contrast administration. There was also an important mass effect with midline structures shifted to the left. The preoperative radiological diagnosis was a complex neoplasm. The histological diagnosis was desmoplastic infantile ganglioglioma (DIG).

The patient underwent surgery with complete resection of the mass.

This pathology appears in infancy (typically under 18 months of age), and affects more males than females. Seizures and/or paresis are the common clinical presentation, frequently associated with rapid head growth. CT imaging shows a great cyst-like lesion, usually in the frontal or parietal lobes, with a small solid peripheral component, which is iso- or hyperdens and shows intense enhancement after contrast administration. Typically there is also contrast enhancement extending to the adjacent meninges. Moderated vasogenic edema can be seen. (2)(3) With MRI the cyst-like component is hypointens on T1-weighted images and hypo- or hyperintens on T2-weigthed images, and the solid part enhances after paramagnetic contrast administration. (2)(3) In the case we are reporting, a cerebral ultrasonography was performed, finding a big anechoic (cystic) lesion, with a smaller similar lesion adjacent to its anterolateral wall. No solid component with different ecogenicity from the cerebral normal parenquima was found. In our bibliographic research there was only one case in which an ultrasonography was performed, and their findings were similar to our, except for an hypoechoic soft-tissue component they described.(4) Histopathologically this is a neuroepithelial tumor with an important cystic component, which is an integral part of the tumor, and a smaller solid component located peripherally and adjacent to the meninges, composed of glial and ganglionar cells associated with an extreme desmoplastic reaction. Immature neuroepithelial cells and necrosis are common findings. The frequent presence of prominent mitotic activity and focal high cellularity can induce misinterpretation of DIG as high-grade tumor. In infantile-age group, differential diagnosis should be made with gangliogliomas, supratentorial ependymomas, PNET and astrocytomas.(2)(3) Differences from ganglioglioma include infantile age presentation, inclusion of immature neuroepithelial cells, intense desmoplastic reaction and dominant location in the parietal or frontal lobes. PNET are usually deeply seated and have areas of necrosis, calcification, haemorrhage and partial quistic formation, as well as important surrounding edema. Supratentorial ependymoma shows heterogeneous contrast enhancement and frequent calcification. Astrocytomas are uncommon in neonatal period, and associated leptomeningeal enhancement is much less common. Pleomorphic xanthoastrocytoma is a rare benign tumor that radiologically can be very similar to DIG, but appears in older children or young adults and is usually temporo-parietal located. Other tumors, which might also be considered in this age group, are malignant teratomas and sarcomas, but imaging features are different from DIG. Surgery with total resection of the tumor is usually curative and there is no need of adjuvant therapies because the prognosis is good.