Congenital Intracerebral Epithelial Cysts

Abstract

The problem of intracerebral congenital epithelial cysts is discussed with reference to five clinical cases. On the basis of their morphological structure the author differentiates the intracerebral cyst with a ciliated, columnar epithelium from the ependymal cyst proper (more frequently located in the lateral recess of the medulla oblongata) and the posterior cerebellar cyst of meningeal arachnoid origin. The cyst with a ciliated columnar epithelium appears to be an ectopic intracerebral tissue, whose neuroepithelial or endodermic origin still remains to be demonstrated. This cyst has been commonly described as a colloid (epithelial) cyst of the 3rd ventricle but may also be localized at other points in the central nervous system. One of the cases studied was an epithelial cyst in the frontal lobe, without any connexion with the ventricle, and evolving as a cerebral tumour.

Osteoma of the frontal sinus complicated by intracranial mucocele

“…Immunostaining for glial fibrillary acidic protein (GFAP) helps to demonstrate neuroglial tissue. Colloid cysts and Rathke cleft cysts resemble each other histologically, and are analogous to the endodermal cyst except for their locations: colloid cysts are in the anterosuperior third ventricle and Rathke cleft cysts are in the intra‐ or suprasellar region 15,18 . Both locations were not involved in our case.…”

“…Colloid cysts and Rathke cleft cysts resemble each other histologically, and are analogous to the endodermal cyst except for their locations: colloid cysts are in the anterosuperior third ventricle and Rathke cleft cysts are in the intra-or suprasellar region. 15,18 Both locations were not involved in our case. Differentiation of the mucocele from the endodermal cyst is entirely based on anatomical findings that indicate a continuity of the cyst with an osteoma or/and the frontal sinus.…”

“…Clinically, a combination of a calcified lesion in the frontal sinus and a nearby cystic lesion in the cranium might include differential diagnoses, such as epidermoid tumor, calcified meningioma, rare gliomas developing extraaxially, parasite infections (cysticercosis and schistosomiasis) and post‐traumatic porencephaly 4,5 , 13,14 . Histopathologically, differential diagnoses for the intracranial mucocele include intracranial epithelial cysts that can be seen in the frontal lobe, such as the endodermal cyst, ependymal cyst, colloid cyst, Rathke cleft cyst, nasal dermoid cyst with intracerebral extension and intracerebral epidermoid cyst 15–18 . Dermoid and epidermoid cysts can be differentiated from the mucocele by the presence of epidermal lining with or without skin appendages underneath, respectively.…”

“…4,5,13,14 Histopathologically, differential diagnoses for the intracranial mucocele include intracranial epithelial cysts that can be seen in the frontal lobe, such as the endodermal cyst, ependymal cyst, colloid cyst, Rathke cleft cyst, nasal dermoid cyst with intracerebral extension and intracerebral epidermoid cyst. [15][16][17][18] Dermoid and epidermoid cysts can be differentiated from the mucocele by the presence of epidermal lining with or without skin appendages underneath, respectively. Endodermal, ependymal, colloid and Rathke cleft cysts are often lined by ciliated columnar epithelium, as in our case.…”