|Year : 2016 | Volume
| Issue : 3 | Page : 363-366
A calcified epidermoid cyst within right lateral ventricle: A report of a rare case
Ranjan Kumar Sahoo1, Debahuti Mohapatra2, Pradipta Tripathy3
1 Department of Radiology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India
2 Department of Pathology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India
3 Department of Neurosurgery, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India
|Date of Web Publication||17-May-2016|
Department of Neurosurgery, Institute of Medical Sciences and SUM Hospital, Sector-8, Kalinga Nagar, Ghatikia, Bhubaneswar - 751 003, Odisha
Source of Support: None, Conflict of Interest: None
A young patient reported to neurosurgery outdoor department with symptoms of increased intracranial pressure. Noncontrast computed tomography examination showed a single calcified mass within right lateral ventricle with mild hydrocephalus. Contrast-enhanced magnetic resonance imaging revealed nonenhancing single mass within right lateral ventricle with mild hydrocephalus. Intraventricular calcified choroid papilloma/calcified epidermoid were radiological differentials. The mass was excised, removed from the lateral ventricles and found to be calcified epidermoid on gross and microscopic examination, which is rare.
Keywords: Epidermoid cyst, intraventricular, lateral ventricle
|How to cite this article:|
Sahoo RK, Mohapatra D, Tripathy P. A calcified epidermoid cyst within right lateral ventricle: A report of a rare case. Med J DY Patil Univ 2016;9:363-6
| Introduction|| |
Epidermoids are congenital benign, slow growing tumors. They represent 0.2-1% of total intracranial tumors  and are seen frequently between 20 and 40 years of age. The most common intracranial location is cerebellopontine angle cistern, sellar/parasellar region,  fourth ventricle and less commonly intracerebral hemisphere or brainstem. Lateral intraventricular epidermoid is a rare entity. Calcification in epidermoid is uncommon and dystrophic in nature. We report a case of right lateral intraventricular calcified epidermoid with mild hydrocephalus in a 30-year-old male patient.
| Case Report|| |
A 30-year-old male patient came to neurosurgery outpatient clinic with complaints of intermittent headache, vomiting, and occasional blurring of vision for 1-year of duration. On examination, his vital signs were stable. His visual acuity was 6/6 in both eyes. Funduscopy examination revealed bilateral mild papilledema. The rest of cranial nerves, motor, and sensory examinations were normal. Noncontrast computed tomography of the head revealed a hypodense mass with an irregular outline, irregular peripheral calcification, and dilated bilateral lateral ventricles [Figure 1]A. Contrast-enhanced magnetic resonance imaging (CEMRI) of brain was advised for characterization of lesion which showed T1 hypointense, T2-weighted (T2W) hyper intense, fluid attenuation inversion recovery (FLAIR) isointense to hyperintense signal, and no postcontrast enhancement of the mass [Figure 1]B-F. The lesion was showing blooming in gradient image and diffusion restriction. The provisional radiological diagnosis was calcified choroid plexus papilloma or calcified epidermoid. The patient was operated through right parietal craniotomy and superior parietal lobule approach. The mass was removed from intraventricular location completely. Large capsulated mass with yellowish cheesy material inside was excised and sent for histopathological study [Figure 2]A. Histopathology examination confirmed the mass as epidermoid [Figure 2]B]. Postoperative period was uneventful. The patient was discharged in good condition without any neurological deficit. Follow-up magnetic resonance imaging (MRI) of the brain shows normal lateral ventricles [Figure 2]C-E.
|Figure 1: (A) Noncontrast computed tomography scan of the head shows lobulated hypodense right intraventricular mass with peripheral calcifi cation and mild hydrocephalus. Magnetic resonance image of brain shows the mass with T1 hypointense (B), T2-weighted hyperintense with hypointense irregular rim (C), Fluid attenuation inversion recovery isointense to hyperintense signal (D), No contrast enhancement in axial image (E), And coronal image (F)|
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|Figure 2: The excised intraventricular calcifi ed capsulated globular mass (A) Shows yellowish cheesy material inside. Microphotograph (B) Shows stratified squamous epithelium of cyst wall with internal keratin content which confirmed it as an epidermoid cyst. Follow-up magnetic resonance imaging image of brain shows normal lateral ventricle (C-E)|
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| Discussion|| |
Intracranial epidermoid develops during 3 rd to 5 th week of the embryonal period due to the inclusion of squamous epithelium remnant in the neural tube when the neural tube separates from ectoderm.  The epidermoid is seen in an intradural location in 90% of cases and extradural location in 10% cases. The common locations of epidermoids are the cerebellopontine angle (40-50%), fourth ventricle (17%), parasellar/sellar (10-15%), and cerebral hemisphere (1.5%). Epidermoid location in intraparenchymal and ventricle is rare (2.7%).  Pathogenesis of intraventricular epidermoid is probably related to the development of choroid vessels which explain the lateral migration through choroid fissure and subsequent entrapment of neuroepithelial cell.  Epidermoid grows slowly due to the accumulation of breakdown product of desquamated epithelium such as keratin and cholesterol, and therefore, present commonly in latter decade of life. The intraventricular epidermoid often have a connection to midline through choroid fissure.  In our case, the epidermoid had an attachment to midline interventricular septum posteriorly.
Due to very few case reports and rarity of the lesion, no definitive clinical symptoms or sign is described to intraventricular epidermoid. Nonspecific symptoms likely headache, cognitive deficit, and psychiatric symptoms have been described in the literature. The patient usually presents in the fifth or sixth decade of life. Most of the lesions are not associated with hydrocephalus due to the pliable nature of cyst and maintained cerebrospinal fluid (CSF) flow by gradual remodeling of adjacent neural tissue.  In our case, the patient present at an earlier age of 30 years with symptoms of intermittent headache and vomiting which may be explained by the loss of pliable nature of epidermoid due to extensive calcification and partial obstruction to CSF flow by epidermoid resulting mild hydrocephalus.
Typical imaging appearance of intracranial epidermoid on computed tomography (CT) study is a round to lobulated hypodense mass with CSF attenuation. Calcification often reported in 10-25% of intracranial epidermoid. A rare dense epidermoid have been described which show high CT attenuation due to protein content or saponification of cyst debris to calcium soap. On MRI, the epidermoid is isointense to slightly hyperintense to CSF signal in T1W and T2W sequences and doesn't suppress CSF signal completely in FLAIR sequence. The lesion shows restriction of diffusion in diffusion-weighted imaging and no postcontrast enhancement. Minimal peripheral enhancement may be seen in 25% of cases.  In our case, the mass shows T1W hypointense, T2W/FLAIR hyperintense signal with mild ventriculomegaly and no significant postcontrast enhancement. On diffusion-weighted and diffusion anisotropy images, the intraventricular epidermoid shows hyperintense signal surrounded by hypointense CSF. Diffusion tensor imaging accentuated its lobulated structure and clearly demonstrated its relationship to neighboring white matter tracts.  The most common differential diagnosis of intraventricular epidermoid is arachnoid cyst and choroid plexus papilloma. Arachnoid cyst shows suppression of fluid signal in FLAIR sequence, no restriction of diffusion in DWI and no contrast enhancement while choroid plexus papilloma shows calcification in lesion along with intense contrast enhancement. 
Intraventricular epidermoids needs surgical excision by appropriate selection of craniotomy site. Epidermoid within the anterior horn can be approached by transcortical-transventricular route while the caudally located lesions are excised through transcallosal route. The epidermoid within temporal horn and choroid fissures can be approached through subtemporal route.  Use of endoscope for intraventricular tumor excision is largely restricted to fenestration of cystic lesion (colloid cyst) and excision of the small soft avascular tumor (<2 cm). Intraventricular small epidermoid can be removed by endoscopically due to its soft and avascular nature.  However, it is difficult to remove large calcified hard epidermoid. Complete excision of epidermoid along with the capsule without injuring choroid vessel, ependyma, and subependymal lining are to be followed meticulously during surgery. Contamination of ventricular cavity from spillage epidermoid content can lead to chemical meningitis and ventriculitis.  In our case, the intraventricular epidermoid was excised completely along with capsule by superior parietal lobule approach.
| Conclusion|| |
Intraventricular epidermoid with calcification is a rare entity and may mimic choroid plexus papilloma in noncontrast CT scan. CEMRI of the brain should be done for better characterization, an extension of mass, and determination of surgical corridor for tumor excision. Complete microsurgical excision with the capsule gives the excellent surgical outcome.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Franko A, Holjar-Erliæ I, Miletiæ D. Lateral ventricle epidermoid. Radiol Oncol 2008;42:66-8.
Akar Z, Tanriover N, Tuzgen S, Kafadar AM, Kuday C. Surgical treatment of intracranial epidermoid tumors. Neurol Med Chir (Tokyo) 2003;43:275-80.
Mohanty S, Bhattacharya RN, Tandon SC, Shukla PK. Intracerebral cystic epidermoid. Report of two cases. Acta Neurochir (Wien) 1981;57:107-13.
Moreno-Jimenez S, Tena-Suck ML, Collado-Ortiz MA, Castillejos-López M, Alvarado-Moreno D, Holland MK. Intracranial epidermoid cyst in a single Mexican institution, experience of over 16-years. Patología 2012;50:182-9.
Osborn AG, Salzman KL, Barkovich AJ. Diagnostic Imaging: Brain. Part-1. Sec. 7, 19. Salt Lake City: Amirsys; 2004.
Delfini R, Acqui M, Oppido PA, Capone R, Santoro A, Ferrante L. Tumors of the lateral ventricles. Neurosurg Rev 1991;14:127-33.
Bhatoe HS, Mukherji JD, Dutta V. Epidermoid tumour of the lateral ventricle. Acta Neurochir (Wien) 2006;148: 339-42.
Osborn AG, Preece MT. Intracranial cysts: Radiologic-pathologic correlation and imaging approach. Radiology 2006;239:650-64.
Koot RW, Jagtap AP, Akkerman EM, Den Heeten GJ, Majoie CB. Epidermoid of the lateral ventricle: Evaluation with diffusion-weighted and diffusion tensor imaging. Clin Neurol Neurosurg 2003;105:270-3.
Shetty A, Nair R, Tripathi P, Kumar V, Upadhyaya S. Endoscopic excision of a lateral ventricular epidermoid - A case report of a novel technique. Int J Surg Case Rep 2014;5: 1135-8.
[Figure 1], [Figure 2]