Ependymoma with cartilaginous metaplasia might have more aggressive behavior: a case report and literature review

Abstract

Ependymoma with cartilaginous metaplasia with or without bone formation is exceedingly rare. Only eight cases have been reported in the literature. We report a case of ependymoma with cartilaginous and osseous metaplasia in a 5-year-old boy. Microscopically, the tumor was composed of neoplastic ependymal tissue and mature cartilage and bone. Immunohistochemically, glial fibrillary acidic protein and epithelial membrane antigen were positive for ependymoma cells but negative for cartilage and bone. Recurrence occurred after 15-month follow-up. The patient deteriorated rapidly and died after 1 month. Reviewing 8 reported cases and our latest case, we found that 3 cases of ependymoma with cartilaginous metaplasia were treated with radiotherapy. Six cases had recurrence from 6 months to 8 years and 2 cases died on the day of operation. These findings suggest that ependymoma with cartilaginous metaplasia might have more aggressive clinical behavior.

Extensive Cartilaginous Metaplasia of Recurrent Posterior Fossa Ependymoma: Case Report and Review of the Literature

“…Cartilaginous metaplasia of paediatric ependymomas was first described by Mackay [2] in 1935 and since then only 14 cases have been reported [2,3]. Mean age was 20 years (1-61), and this is only the 3rd case that was originally diagnosed under the age of 3 [3,4,5].…”

“…In 3 reports no official grading was mentioned [2,3,7,8]. Ghosal et al [9] described a patient that was initially diagnosed as a grade II ependymoma with chondroid metaplasia, which progressed to grade III 12 months after resection.…”

“…Of 12 cases that were tested for epithelial membrane antigen 58% were found positive, and all 7 cases tested for S-100 protein were positive [3,4,5]. …”

“…Mean age was 20 years (1-61), and this is only the 3rd case that was originally diagnosed under the age of 3 [3,4,5]. The most common location is the 4th ventricle (12 cases, 73.3%); 1 was prepontine extending to the suprasellar region and 2 were supratentorial (temporo-occipital, frontal lobes) [3,4,5,6]. …”

“…Cartilaginous metaplasia was found on the initial operation in 7 cases (64%), on the 2nd operation following adjuvant radiotherapy in 1 (9%) and on the 3rd operation following radiotherapy in 2 (18%) [3,4,5,10]. Our patient was the only one to have 5 resections in total and histological findings progressed from a grade II to more aggressive grade III anaplastic ependymoma following a year of chemotherapy and then, after a course of radiotherapy, to ependymoma with cartilaginous metaplasia.…”