Neurol India Home 

Year : 2010  |  Volume : 58  |  Issue : 4  |  Page : 676--677

Cerebellopontine angle endodermal cyst: A rare occurrence

Diyora Batuk1, Yoshida Koichiro2, Kawase Tsukasea2, Kanno Tetsuo2, Motomi Ando2,  
1 Department of Neurosurgery, L.T.M.G. Hospital, Sion, Mumbai, India
2 Fujita Health University, Japan

Correspondence Address:
Diyora Batuk
Department of Neurosurgery, L.T.M.G. Hospital, Sion, Mumbai

How to cite this article:
Batuk D, Koichiro Y, Tsukasea K, Tetsuo K, Ando M. Cerebellopontine angle endodermal cyst: A rare occurrence.Neurol India 2010;58:676-677

How to cite this URL:
Batuk D, Koichiro Y, Tsukasea K, Tetsuo K, Ando M. Cerebellopontine angle endodermal cyst: A rare occurrence. Neurol India [serial online] 2010 [cited 2023 Feb 4 ];58:676-677
Available from:

Full Text


Endodermal cysts are rare congenital lesions of central nervous system (CNS) and usually occur in the posterior cranial fossa. [1] Endodermal cyst in the cerebellopontine angle is very rare. [2],[3] Imaging provides the anatomical details, but improved immunohistological techniques provide the definitive diagnosis. The cyst needs complete removal and recurrence is common with incomplete removal.

A 66-year-old female presented with progressive gait ataxia of four months duration. Neurological examination revealed right cerebellar signs. Computed tomography (CT) revealed non-contrast enhancing low-density cystic lesion in the right CP angle [Figure 1]. Magnetic resonance (MR) imaging also revealed non-contrast enhancing cystic lesion in the right CP angle, which was homogenously hypointense on T1- weighted image and homogenously hyperintense on T2-weighted images [Figure 2] and [Figure 3]. Patient had right sub-occipital craniectomy and complete excision of the cyst by microsurgery. Frozen section study suggested epithelial nature of the cyst. Cyst content was creamy white colloid fluid. Histopathological examination showed non-ciliated columnar epithelial cells with focal pseudo stratified arrangement [Figure 4]. Immunohistochemical studies revealed that the cells were positive for carcinoembryonic antigen and epithelial member antigen but negative for S-100 protein and glial fibrillary acidic protein. She had uneventful postoperative recovery and resolution of cerebellar signs.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

The cysts in posterior cranial fossa.can be epithelial, mesenchymal or mixed in origin. [3] Epithelial cysts are rare CNS cystic lesion and are of two types, endodermal (neurenteric) and neuroepithelial (ependymal and choroidal). Endodermal cyst is lined with endodermal epithelium. Enterogenous, neuroenteric, foregut, bronchogenic and respiratory cyst are the other names according to the epithelial lining of the cyst wall. [4] The first report, three cases, of intracranial endodermal cyst was by Small. [5] Pathogenesis of the posterior fossa endodermal cysts is yet to be understood. Endodermal - ectodermal adhesion, split notochord or neurenteric band, disorder of gastrulation and persistence of the neurenteric canal are the possible explanations for the location of these lesions in the posterior fossa. Cyst content varies and includes clear, mucinous fluid, browny necrotic material, milky white liquid, viscous yellow fluid and cheesy grumous material. Differential diagnosis includes the arachnoid cyst, epidermoid cyst, neuroepithelial cyst, cystic schwannoma and inflammatory cysts such as cysticercosis. Steady-state free precession (SSFP) imaging is useful in differentiating lesions such as epidermoid from simple or complex benign cyst. Diffusion weighted MR can distinguish arachnoid cyst and epidermoid cyst. [6] Immunohistochemical stains are useful for the differential diagnosis, endodermal cysts are positive for cytokeratine and carcinoembtyonic antigen (CEA) in endodermal cyst and negative in neuroepithelial cyst. [3],[7] The treatment of choice for intracranial endodermal cysts is fenestration of the cyst and removal of the cyst wall. Since recurrence of endodermal cyst after fenestration alone has been reported, complete removal of the cyst wall is recommended. [8]


1Bejjani GK, Wright DC, Schessel D, Sekhar LN. Endodermal cysts of the posterior fossa. Report of three cases and review of the literature. J Neurosurg 1998;89:326-35.
2Muller J, Voelker JL, Campbell RL. Respiratory epithelial cyst of the cerebellopontine angle. Neurosurgery 1989;24:936-9.
3Leung Sing THK, Fung CF, Fan Yw. An epithelial cyst in the cerebellopontine angle. case report. J Neurosurg 1991;74:278-82.
4Ray A, Chakraborty A, Donaldson-Hugh M. Enterogenous cyst of the posterior fossa. Br J Neurosurg 2000;14:249-51.
5Small JM. Pre axial enterogenous cysts. J Neurol Neurosurg Psy 1962;25:184.
6Tsuruda JW, Chew CM, Mosely ME, Norman D. Diffusion weighted MR imaging of the brain: Value of differentiating between extraaxial cyst and epidermoid tumors. AJNR Am J Neuroradiol 1990;11:925-31.
7Inoue T, Matsushima T, Fukui M, Iwaki T, Takeshita I, Kuromatsu C. Immunohistochemical study of intracranial cyst. Neurosurgery 1988;23:576-81.
8Andrews BT, Halks-Miller M, Berger MS, Rosenblum ML, Wilson CB. Neuroepithelial cyst of the posterior fossa: pathogenesis and report of two cases. Neurosurgery 1984;15:91-5.