Background: Better understanding of embryology, histopathology and genetics of dysraphic conditions have lead to an expansion of this concept to entities with a similar microscopic appearance (e.g. enterogenous cysts, colloid cyst of the III-rd ventricle) or rated among neoplasms (e.g. mature teratoma), creating a certain conceptual confusion. Currently the diagnosis of "teratoma" is being substituted by "enterogenous cyst" or "teratomatous cyst".
Aim of paper: Clarification of concepts in this field and presentation of the experience of the Department of Neurosurgery of the Children's Memorial Health Institute associated therewith.
Material and method: Since January 1990 through April 2005 we had treated 7 children with the final diagnosis of "an enterogenous cyst". The mean age of the children was 10.5 years and the mean follow-up time was 4.1 years. The study was performed by a retrospective analysis of medical records, imaging studies and histological preparations.
Results: the study group included: 3 cases of type I enterogenous cyst, 1 case of type II cyst and 3 cases of type III cyst (in 2 cases a former diagnosis of "mature teratoma" has been revised). Within this follow-up time, a good outcome was obtained in 3 cases, moderate disability - in 3 cases and severe disability - in 1 case.
Conclusions: (1) Enterogenous cyst often co-exists with other dysraphic features; (2) Clinical signs of an enterogenous cyst are non-typical and depend on location of the lesion. The presence of secreting gastric mucosa may lead to chemical myelitis; (3) Severity of the postoperative neurological deficit is due to the developmental nature of the lesion and common vascular supply; (4) Late results of treatment are satisfactory, provided the lesion is excised radically; (5) Enterogenous cyst may be diagnosed in the case of a tumor composed of tissues originating from 1, 2 or 3 embryonic layers coexisting with dysraphic stigmata, congenital vertebral abnormalities or a mediastinal tumor of the same type. Types II and III of enterogenous cyst were historically diagnosed as "adult teratoma".