Although rare, GI GCTs have characteristic clinicopathological features. Nestin may be a useful immunohistochemical marker for identifying these tumours; the presence of this persistent stem cell cytoskeletal filament within GI GCTs suggests that these lesions may arise from a multipotential stem cell in the GI tract.

Intraventricular neurocytoma (IN), a recently recognized, benign cerebral tumor of young adults, can be confused with oligodendroglioma and other neoplasms. The authors compared the radiologic features of six pathologically confirmed cases of IN with those of 26 previously reported cases. The presenting symptoms were headache (62%), raised intracranial pressure (41%), and seizures (12%). Radiologically, the tumor frequently demonstrated a characteristic attachment to the septum pellicidum and confinement to the lateral and third ventricles. Calcification, which is common in IN and an important diagnostic feature, was seen to best advantage on computed tomographic (CT) scans. The results indicate that IN can be suggested radiologically on the basis of its CT appearance and should be included in the pathologic differential diagnosis of intraventricular tumors.