Subependymomas – Characteristics of a “Leave me Alone” Lesion

Abstract

Purpose Intracranial subependymomas are rare, mostly asymptomatic tumours, which are often found incidentally and therefore did not receive much attention in previous literature. By being classified as benign grade I in the WHO classification of tumours of the central nervous system, they are given a special status compared to the other ependymal tumours. Tumor recurrences are a rarity, spinal “drop metastases” do not occur. While etiological, pathological and therapeutic characteristics have been subject of several publications over the last few decades and have meanwhile been well studied, the imaging characteristics are much less well received.

Material and method Retrospective analysis of our relatively large group of 33 patients with subependymoma, including 4 patients with a mixture of subependymomas with ependymal cell fractions in terms of imaging and clinical aspects and with reference to a current literature review.

Results Subependymomas have typical image morphologic characteristics that differentiate them from tumors of other entities, however, the rare subgroup of histopathological mixtures of subependymomas with ependymal cell fractions has no distinctly different imaging properties.

Conclusions Knowing the imaging characteristics of subpendymoma and their differential diagnoses is of particular importance in order to be able to decide between the necessity of follow-up controls, an early invasive diagnosis or, depending on the entity, tumor resection.

Key Points: 

• Subependymomas have typical imaging characteristics that are clearly distinguishable from other entities.

• Increased incidence in middle/ older aged men, most frequent localization: 4th ventricle.

• Symptomatic subependymomas, often located in lateral ventricles, are usually characterized by hydrocephalus.

• Radiological identification of mixed subependymoma with ependymal cell fractions is not possible.

• Image based differentiation from other entities is important for the procedure.

Citation Format

• Kammerer S, Mueller-Eschner M, Lauer A et al. Subependymomas – Characteristics of a “Leave me Alone” Lesion. Fortschr Röntgenstr 2018; 190: 955 – 966

Key words

subependymom - subependymoma mri - subependymome review - MR-imaging

• Literatur

• 1 Bernd W. Scheithauer. Symptomatic subependymoma. Journal of Neurosurgery 1978; 49: 689-696
• 2 Ernestus RI, Schroder R. Clinical aspects and pathology of intracranial subependymoma – 18 personal cases and review of the literature. Neurochirurgia 1993; 36: 194-202
• 3 Rushing EJ, Cooper PB, Quezado M. et al. Subependymoma revisited: clinicopathological evaluation of 83 cases. Journal of Neuro-Oncology 2007; 85: 297-305
• 4 Hernández-Durán S, Yeh-Hsieh TY, Salazar-Araya C. Pedunculated intraventricular subependymoma: Review of the literature and illustration of classical presentation through a clinical case. Surgical Neurology International 2014; 5: 117
• 5 Scheinker IM. Subependymoma: A Newly Recognized Tumor of Subependymal Derivation. Journal of Neurosurgery 1945; 2: 232-240
• 6 Zhou S, Xiong J, Pan J. et al. Neuroradiological features of cervical and cervicothoracic intraspinal subependymomas: a study of five cases. Clinical radiology 2016; 71: 499.e9–15
• 7 Hoeffel C, Boukobza M, Polivka M. et al. MR manifestations of subependymomas. American journal of neuroradiology 1995; 16: 2121-2129
• 8 Maiuri F, Gangemi M, Iaconetta G. et al. Symptomatic subependymomas of the lateral ventricles. Report of eight cases. Clinical neurology and neurosurgery 1997; 99: 17-22
• 9 Fujisawa H, Hasegawa M, Ueno M. Clinical features and management of five patients with supratentorial subependymoma. Journal of Clinical Neuroscience 2010; 17: 201-204
• 10 Ragel BT, Osborn AG, Whang K. et al. Subependymomas: an analysis of clinical and imaging features. Neurosurgery 2006; 58: 881-890 ; discussion -90
• 11 Tiwari N, Powell SZ, Takei H. Recurrent subependymoma of fourth ventricle with unusual atypical histological features: A case report. Pathology international 2015; 65: 438-442
• 12 Chiechi MV, Smirniotopoulos JG, Jones RV. Intracranial subependymomas: CT and MR imaging features in 24 cases. American Journal of Roentgenology 1995; 165: 1245-1250
• 13 Louis DN, Wiestler OD. Cancer IAfRo. WHO Classification of Tumours of the Central Nervous System. International Agency for Research on Cancer; 2016
• 14 Jain A, Amin AG, Jain P. et al. Subependymoma: clinical features and surgical outcomes. Neurological research 2012; 34: 677-684
• 15 Zhiyong B, Xiaohui R, Junting Z. et al. Clinical, radiological, and pathological features in 43 cases of intracranial subependymoma. Journal of Neurosurgery 2015; 122: 49-60
• 16 Kim Y, Lee SY, Yi KS. et al. Infratentorial and intraparenchymal subependymoma in the cerebellum: case report. Korean journal of radiology 2014; 15: 151-155
• 17 Koral K, Kedzierski RM, Gimi B. et al. Subependymoma of the cerebellopontine angle and prepontine cistern in a 15-year-old adolescent boy. American journal of neuroradiology 2008; 29: 190-191
• 18 Smith AB, Smirniotopoulos JG, Horkanyne-Szakaly I. From the Radiologic Pathology Archives: Intraventricular Neoplasms: Radiologic-Pathologic Correlation. RadioGraphics 2013; 33: 21-43
• 19 Lombardi D, Scheithauer BW, Meyer FB. et al. Symptomatic subependymoma: a clinicopathological and flow cytometric study. Journal of Neurosurgery 1991; 75: 583-588
• 20 Jooma R, Bradshaw J, Brownell B. et al., editors Subependymoma of the 4th ventricle-a surgical series. Journal of Neurology Neurosurgery and Psychiatry. Tavistock Square, London, England WC1H 9JR: British Med Journal Publ Group British Med Assoc House; 1985
• 21 Rea GL, Akerson RD, Rockswold GL. et al. Subependymoma in a 2 1/2-year-old boy. Case report. J Neurosurg 1983; 59: 1088-1091
• 22 Shah T, Jayasundar R, Singh VP. et al. In vivo MRS study of intraventricular tumors. Journal of magnetic resonance imaging: JMRI 2011; 34: 1053-1059
• 23 Bi Z, Ren X, Zhang J. et al. Clinical, radiological, and pathological features in 43 cases of intracranial subependymoma. J Neurosurg 2015; 122: 49-60
• 24 Zimmer C, Korf B, Ebel H. et al. Zentrales Neurozytom. Akt Neurol 1993; 20: 132-137
• 25 Osborn AG. Osborn’s Brain: Imaging, Pathology, and Anatomy. Amirsys; 2013