gms | German Medical Science

Chordoid gliomas, formerly classified as ependymoastrocytomas, are a rare entity primarily seen in middle-aged female patients. They are typically located in the hypothalamus and third ventricle and correspond to WHO grade II. We present the case of a 32-year-old woman with an atypical glioma of the hypothalamus and third ventricle.

The patient presented with an acute onset of headache, vomiting and gait ataxia. The CCT showed an inhomogeneous tumor with contrast enhancement and calcifications located in the third ventricle. A massive secondary internal hydrocephalus was treated with two external CSF drainages on the day of admission. Two days later, the tumor was completely resected. After a follow-up of 10 months, the patient had no neurological deficit and the tumor has not recurred so far. Besides a small calcification, the tumor showed the well-known imaging characteristics of chordoid gliomas. Histopathologically the glial tumor was made up of three components: first - areas of ependymal cell growth, second - areas of astrocytic cell growth and third - a cartilaginous component.The immunohistochemical study showed that most tumor cells were positive for GFAP and S100 – protein, but negative for cytoceratin and EMA. Typically, the tumor had a low proliferation index (MIB 1) of <3%.

Although not described in the literature so far, this tumor with its cartilaginous component could be classified as a subtype of chordoid gliomas. The localization, the epidemiological as well as the imaging characteristics and the immunohistopathology are similar to these tumors. Atypical is the fact that this tumor is missing strands and cords of epitheloid cells. Chordoid gliomas were first described by Brat in 1998 as third ventricular glial neoplasms with a chordoid appearance and classified in the year 2000 by the WHO as a separate tumor entity of the WHO grade II group. So far 33 cases have been described in literature.

Chordoid gliomas are unusually rare glial tumors, classified by the WHO in the year 2000 with an inhomogeneous histopathological presentation. The histiogenesis is uncertain but an ependymal differentiation has been discussed. Our case does not show the typical cords of epitheloid cells but presents with a cartilaginous component. It may be a new subtype or borderline tumor of this entity.