1/3. ependymoma with neuropil-like islands: a case report with diagnostic and histogenetic implications.We describe a case of ependymoma with neuronal differentiation in form of neuropil-like islands. A 6-year-old boy presented at clinical examination for a short history of headaches and vomiting. brain computed tomography showed a large, partially cystic, parieto-occipital lesion. The tumor was composed by glial fibrillary acidic protein-positive round cells with a perivascular arrangement and scattered neuropil-like islands, showing intense positivity for synaptophysin. Despite radiotherapy, the tumor recurred, showing frank features of anaplasia, but lacking the neuropil-like islands. The histological features of the tumor are discussed in the light of the concept that neuronal differentiation can occur occasionally in gliomas of different lineage without affecting the expected biological behavior.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
2/3. Ependymal rests and subcutaneous sacrococcygeal ependymoma.A 2 cm subcutaneous ependymoma was resected from the natal cleft of a 4-yr-old girl. The coccyx was not removed and there has been no recurrence in 14 years. A study of the post-coccygeal region in 15 control infants revealed subcutaneous islands of ependyma, unconnected with the cauda equina, in 4/4 infants with post-anal dimples and in 6/11 infants with no external post-coccygeal anomaly.- - - - - - - - - - ranking = 0.14285714285714keywords = island (Clic here for more details about this article) |
3/3. gliosarcoma developing from an irradiated ependymoma.A 17-year-old girl was operated for a cystic mass located deep within the left parieto-occipital white matter. Histologically the tumor was an ependymoma with a vascular stroma. In spite of irradiation the tumor recurred locally twice, 1 and 2 years respectively after the original operation. The ependymoma portion of the tumor remained unchanged, but the stroma showed increased vascular hyperplasia at the time of the second operation and transformation into a fibrosarcoma in the third operative specimen. Proliferating cell markers (MIB-1) were positive only in the ependymoma cell nuclei in the first two specimens, but were also extensively present in the nuclei of the fibrosarcoma in the third specimen. In the latter, the fibrosarcoma portion greatly overwhelmed the residual ependymoma islands, but remained sharply delineated from them. This is the first observed case of a gliosarcoma originating from an ependymoma. The histological pattern of this mixed tumor clearly indicates that the source of the sarcomatous portions was the neoplastically transformed fibrovascular stroma of the original tumor, rather than "desmoplastic" alterations of the neoplastic ependymal cells themselves.- - - - - - - - - - ranking = 0.14285714285714keywords = island (Clic here for more details about this article) |