Giant-cell ependymoma: Presentation of a case of the sacral region and literature review

Abstract

Ependymoma is a rare central nervous system neoplasm with an even rarer morphologic variant called giant-cell ependymoma (GCE). GCE has a characteristic discrepant, malignant-like morphology but indolent behavior. We present the case of a 21-year-old female with an extra-axial GCE located in the sacral region. To date, 16 cases of sacral GCE have been reported in the literature, with 4 cases in the sacral region; however, all those cases were intra-axial. We present the first case of an extra-axial sacral GCE.

Report of a case of giant cell ependymoma with unusual clinical and pathological presentation

“…1 Eighteen out of the 24 (75%) reported GCE cases showed some expression of EMA. 5,7,10,13,15,17,18,[20][21][22][23][24]27,29,30 Our case was negative for EMA, but we observed a dot-like pattern with AE1/AE3. This pattern was very useful for us at the initial study of the tumor when we thought it was a malignant epithelioid tumor because the pattern with AE1AE3 resembled the kind of EMA immunoreactivity usually observed in ependymomas.…”

“…AE1/AE3 was performed in nine out of the 34 reported cases. 2,5,7,8,11,14,18,29 It turned out positive only in three cases, 2,14 none of which showed a dot-like pattern. The WHO Classification of Tumors of the CNS mentioned that AE1/AE3 can be positive in some ependymomas, especially in MPE, 34 but it does not describe a dot-like pattern.…”

“…32 The behavior of GCE of soft tissue should be similar to that of MPE of soft tissue, and treatment should include complete resection, with irradiation in case of local residual tumor burden. 33 Histologically, 14 cases showed areas of classic ependymoma 5,[7][8][9][10][11]13,19,21,23,24,29 and five cases showed regions of MPE, 2,17,20 including ours. In 13 cases, tumors did not present components of other variants of ependymoma.…”

“…considered that the nuclear pleomorphism represented degenerative changes similar to ancient schwannomas. So far, there are only 34 reported cases in the English literature, and only one of them was located in the sacral subcutaneous region . Here we present the second case located in that area, which was resected after being clinically diagnosed as a pilonidal cyst.…”

“…So far, there are only 34 reported cases in the English literature, and only one of them was located in the sacral subcutaneous region. 29 Here we present the second case located in that area, which was resected after being clinically diagnosed as a pilonidal cyst. We reviewed the literature and describe the main clinical features and differential diagnosis of GCE.…”