Subependimoma

Subependymoma of the Cervicothoracic Spinal Cord

Yvan Maque-Acosta1 , Carol K Petito1 , Michael E Ivan2 , Charif Sidani3 and Macarena I de la Fuente4,5*

1 Departments of Pathology, University of Miami, Florida, USA
2 Department of Neurosurgery, University of Miami, Florida, USA
3 Department of Radiology, University of Miami, Florida, USA
4 Department of Neurology, University of Miami, Florida, USA
5 Sylvester Comprehensive Cancer Center, University of Miami, Florida, USA

Background

Subependymomas are rare, World Health Organization (WHO) grade I tumors [1,2]. They typically arise in the ventricles and represent less than 1% of intracranial tumors [3]. Spinal subependymomas are even less frequent, comprising approximately 2% of all symptomatic spinal cord tumors [4]. They are usually intramedullary and located in the cervical region, however thoracic and lumbar lesions have also been reported [2,5,6].

Radiologically, intracranial subependymomas present as well defined intraventricular lesions that are classically T2-weighted images (WI) hyper intense and T1WI hypo or isointense to white matter in MRI [5,7]. Heterogeneity on T2WI is often reported and is related to cystic changes, blood products or calcifications, particularly in larger lesions [5]. Calcifications and blood products can manifest as low signal intensity on T2WI gradient echo sequence. Subependymomas typically do not enhance or only mildly enhance. Avid enhancement has been reported particularly in lesions located in the fourth ventricle. The tumor size typically ranges from 1 to 2 cm, however lesions greater than 5 cm have also been reported [2,5]. Spinal subependymomas usually present as eccentric, well-defined lesions with mild to moderate enhancement. Lesions of the spine have significant associated edema [2,6].

Histologically, subependymomas are characterized by the presence of nuclear clustering and a densely fibrillar and paucicellular background [1]. Microcysts can be present, particularly in lesions located closer to the foramen of Monro. Subtle pseudorosettes can also be seen [1,8]. In tumors located far from the foramen of Monro, the nuclear clustering is more prominent. Occasionally, an ependymoma component can be identified, although this is more common in fourth ventricle tumors. By immunohistochemistry, subependymoma are diffusely positive for glial fibrillary acidic protein (GFAP) which demonstrate its glial origin and positive for epithelial membrane antigen (EMA) (showing a dot-like pattern) which is consistent with an ependymal origin. They usually have a low Ki-67 proliferative index, although it can be variable [1,8].

We describe a case of spinal subependymoma and discuss the clinical, radiographic and histological characteristics.

Citation: Maque-Acosta Y, Petito CK, Ivan ME, Sidani C, de la Fuente MI (2016) Subependymoma of the Cervicothoracic Spinal Cord. J Neurol Neurobiol 2(3): doi http://dx.doi.org/10.16966/2379-7150.123

Avaliable: https://www.sciforschenonline.org/journals/neurology/JNNB-2-123.php

Md. Yvan Maque-Acosta, Ex-Miembro GII