Cerebellopontine angle subependymoma without fourth ventricle extension: An uncommon tumor in a rare location

Abstract

Subependymomas are benign tumors that occur predominantly in the ventricular system. We describe a case of a 57-year-old man with a large cerebellopontine angle (CPA) tumor which expanded into the jugular foramen. Complete surgical excision of the tumor was achieved through a retrosigmoid approach and the histopathological diagnosis was subependymoma. Subependymomas located exclusively in the CPA without extension into the fourth ventricle are extremely rare. The mainly pathological features and the difficulty in correctly diagnosing these cases preoperatively, even with MRI, are discussed.

Large Subependymoma Inferior to the Cerebellopontine Angle With Significant Obstructive Hydrocephalus: A Case Report on an Extremely Rare Tumor

“…In fact, complete resection, when possible, is often curative and favored as subependymomas are benign, indolent, and noninfiltrative [6]. However, treatment should prioritize safely resecting the tumor, decompressing neural elements, establishing a pathological diagnosis, and restoring normal pathways for cerebrospinal fluid [13].…”

“…Due to their indolent growth rate, the likelihood that they remain asymptomatic throughout life is significant [ 6 ]. They frequently develop in the fourth ventricle (50%-60% of cases); followed by the lateral ventricles (30%-40% of cases); and, to a lesser extent, the third ventricle, spinal cord, and septum pellucidum [ 13 ]. It is, thus, extremely rare for subependymomas to develop in extraventricular sites, particularly when they are confined within the CPA [ 6 , 12 , 14 ].…”

“…After a thorough review of the literature found on PubMed, Ovid MEDLINE, and EMBASE, four adult case reports were included and summarized, including the one we presently report, a 51-year-old male with a significant right low CPA subependymoma (Table 1 ). Cunha et al published a case of a 57-year-old male with a large left CPA subependymoma, which expanded into the jugular foramen [ 13 ]. Hoeffel et al presented eight cases, one of which described a case of a 52-year-old male with a subependymoma that developed in the left CPA and extended to the foramen of Luschka [ 9 ].…”

“…In fact, complete resection, when possible, is often curative and favored as subependymomas are benign, indolent, and non-infiltrative [ 6 ]. However, treatment should prioritize safely resecting the tumor, decompressing neural elements, establishing a pathological diagnosis, and restoring normal pathways for cerebrospinal fluid [ 13 ]. Furthermore, it appears that the relationship between the extent of resection and survival rates is insignificant; age at the time of surgery seems to be the only variable that significantly affects survival, with patients over 50 years of age having a worse prognosis [ 11 ].…”

Clinical features and management of intracranial subependymomas in children

“…11 Subependymomas located in the fourth ventricle with extension towards the CPA are unusual, 12 and an exclusive CPA location is particularly rare. 9,13 After reviewing the pertinent Englishlanguage literature, only five CPA-exclusive subependymomas without extension into the fourth ventricle have been reported, 1,9,[13][14][15] one of which was in a paediatric patient, 9 therefore, our CPA-exclusive subependymoma was the sixth ever reported and the second in a paediatric patient.…”