Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 6018  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
  » Next article
  » Previous article 
  » Table of Contents
 Resource Links
  »  Similar in PUBMED
 »  Search Pubmed for
 »  Search in Google Scholar for
 »Related articles
  »  Article in PDF (25 KB)
  »  Citation Manager
  »  Access Statistics
  »  Reader Comments
  »  Email Alert *
  »  Add to My List *
* Registration required (free)  

  In this Article
 »  Abstract
 »  Introduction
 »  Case report
 »  Discussion
 »  References

 Article Access Statistics
    PDF Downloaded164    
    Comments [Add]    
    Cited by others 9    

Recommend this journal

Year : 2000  |  Volume : 48  |  Issue : 2  |  Page : 158-60

Hyperdense intracranial epidermoid : an uncommon presentation.

Department of Neurosurgery, King Edward Memorial Hospital and Seth G. S. Medical College, Parel, Mumbai, 400012, India.

Correspondence Address:
Department of Neurosurgery, King Edward Memorial Hospital and Seth G. S. Medical College, Parel, Mumbai, 400012, India.
[email protected]

  »  Abstract

A thirty year old female presented with sudden onset of severe headache, papilloedema and altered sensorium. Computerised tomography (CT) scan showed a hyperdense vermian mass in the posterior fossa. Operative findings and histological examination revealed spontaneous bleed into the epidermoid cyst. Difficulty in the preoperative diagnosis and uncommon presentation of the intracranial epidermoid cyst prompted us to report this case.

How to cite this article:
Gupta S, Vaishya N D, Senger R L. Hyperdense intracranial epidermoid : an uncommon presentation. Neurol India 2000;48:158

How to cite this URL:
Gupta S, Vaishya N D, Senger R L. Hyperdense intracranial epidermoid : an uncommon presentation. Neurol India [serial online] 2000 [cited 2022 Aug 13];48:158. Available from: https://www.neurologyindia.com/text.asp?2000/48/2/158/1555

   »   Introduction Top

Intracranial epidermoid cyst is commonly found in third and fourth decades of life. Cerebellopontine angle and parasellar regions are the commonest locations. Density of epidermoid cyst on CT scan is mostly between -2 to +10 hounsfield units (HU).[1] A rare case of hyperdense epidermoid due to spontaneous haemorrhage in the cyst is reported and the literature on the various factors resulting in CThyperdense epidermoid cyst is reviewed.

   »   Case report Top

A 30 year old woman presented in first trimester of pregnancy, with history of headache for the last four months. Central nervous system examination revealed mild papilloedema and truncal ataxia. She refused CT scan at that time. Ten days after delivery, she had severe headache with vomiting and within half an hour she became drowsy. On examination, she was disoriented and had gross papilloedema and nystagmus. Eye movements, corneal and gag reflexes were normal. There was no history of trauma. CT scan revealed a well-circumscribed heterogenous hyperdense lesion without peripheral oedema in the vermian region of posterior fossa. The attenuation value of the lesion was 110 HU [Figure. 1]. Fourth ventricle was compressed anteriorly. Preoperative diagnosis of spontaneous haemorrhage in a tumour was made. She was explored through the midline suboccipital craniotomy. A large cyst with yellowish thin walled capsule containing brownish cheesy material was seen. The capsule along with its contents was removed completely. Postoperative period was uneventful and she regained consciousness immediately after surgery and recovered completely. Histopathological examination showed that the capsule was made up of stratified squamous epithelium with extensive haemosiderin deposits in the cells. Patient has been followed up for five years and she is asymptomatic now. CT scan after five years of surgery did not reveal recurrence of lesion.

   »   Discussion Top

Intracranial epidermoid cysts comprise of 0.2% to 1% of all intracranial neoplasms.[1] They arise from displaced midline ectodermal cells between third to fifth weeks of gestation, during closure of the neural tube. These tumours have an affinity for basal subarachnoid cisterns and they enlarge slowly through accumulation of normally dividing cells with growth rate resembling the growth of human epidermis.[2]
Clinical presentation is therefore typically prolonged. Acute presentation, as seen in the present case, is an uncommon presentation of intracranial epidermoid cyst.
CT scan is the single most important investigation for the diagnosis of epidermoid cyst. Characteristic CT scan appearance of epidermoid cyst include an irregular, well demarcated, low density lesion without contrast enhancement. The low density is attributed to lipid component and cholesterol.[1] Calcification is rare in epidermoid and is usually marginal, probably due to peritumoural leak of its contents with secondary dystrophic calcification. Hyperdense epidermoids are very rare. Hasegawa et al[1] and Tekkok et al[2] reviewed hyperdense epidermoids and found a total of eleven reports of thirteen cases of CT-hyperdense epidermoids. Ten of these cases were posterior fossa epidermoids. Four more CT hyperdence epidermoids have been reported[3],[4],[5],[6],[7] in corpus callosum, midline posterior fossa and CP angle.
Braun et al[8] reported 3 cases of hyperdense epidermoid and suggested that the keratinised debris and its saponification to calcium soaps were the cause of the homogeneous hyperdensity of these masses. Chemical contents in a case of hyperdense posterior fossa epidermoid were examined for attenuation value on CT scan and it was concluded that the high density was due to the protein concentration.[9] Various other authors also attributed protein concentration as the cause of hyperdensity in these cases.[5],[6],[10] Tekkok et a1[2] however reported that abundance of polymorphonuclear leucocytes contributed to hyperdensity. A mixed density epidermoid attached to dura of frontal convexity extending into cerebral parenchyma with enhancing capsule was reported by Watanabe et al.[11]
There are only two reports of the spontaneous haemorrhage as the cause of hyperdensity of intracranial epidermoid on CT scan.[1],[12] However, in both these cases, presentation was not acute, as was seen in the present case. Hasegawa et al[1] suggested that haemorrhage occurs continuously or intermittently from the small fibrous nodules containing numerous vessels, which lead to haemosiderin deposits in the cells; and that was the cause of hyperdensity on CT scan. Haemosiderin deposits in the cells were also seen in the present case. Two cases of hyperdense epidermoid following head injury have been reported.[7],[13] Abou et al[13] reported a case of frontal epidermoid along with a large subacute extradural haematoma following minor head injury. At surgery, continuity of extradural haematoma with epidermoid was seen and the cyst was partially filled with haemolysed blood. Haemorrhage in the wall of cyst as the cause of extradural haematoma was suspected.

  »   References Top

1.Hasegawa H, Bitoh S, Nakata M et al: Intracranial epidermoid mimicking meningioma. Surg Neurol 1980; 15: 372-374.   Back to cited text no. 1    
2.Tekkok IH, Cataltepe O, Saglam S: Dense epidermoid cyst of the cerebellopontine angle. Neuroradiology 1991; 33(3): 255-257.   Back to cited text no. 2    
3.Furuhata S, Yamada F, Fukuda S et al: Epidermoid cysts of the callosal region-three case reports. Neurol Med Chir (Tokyo) 1993; 33(10): 697-699.   Back to cited text no. 3    
4.Miyagi K, Imaizumi T, Yamanouchi H et al: Unusual CT and 10. Nagashima C, Takahama M, Sakaguchi A: Dense MRI appearance of the epidermoid tumour: A case report. cerebellopontine epidermoid cyst. Surg Neurol 1982; 17: No To Shinkei 1993; 45(2): 177-181. 172-177.   Back to cited text no. 4    
5.Timmer FA, Sluzewski M, Treskes M et al: Chemical analysis 11. Watanabe K, Wakai S, Nagai M et al: Epidermoid tumour of an epidermoid cyst with unusual CT and MR with unusual CT and MR findings: A case report. Neurol Med characteristics. AJNR 1998; 19(6): 1111-1112. Chir (Tokyo) 1990; 30(12): 977-979.   Back to cited text no. 5    
6.Ochi M, Hayashi K, Hayashi T et al: Unusual CT and MR 12. Dunn RC, Archer CA, Rapport RL11 et al: Unusual CT dense appearance of an epidermoid tumour of the cerebellopontine posterior fossa epidermoid cyst: A case report. J Neurosurg angle. AJNR 1998; 19(6): 1113-1115. 1981; 55: 654-656.   Back to cited text no. 6    
7.Hsieh CH, Huang KM, Kao MC et al: Haemorrhage in 13. Abou-Samara M, Marlin AE, Story JL et al: Cranial intracranial epidermoid cyst. J Formo Med Assoc 1996; 95(2) epidermoid tumour associated with subacute extradural: 173-175. haematoma. J Neurosurg 1980; 53: 574-575.   Back to cited text no. 7    
8.Braun IF, Naidich TP, Leeds NE et al: Dense intracranial epidermoid tumours. Radiology 1977; 122: 717-719.   Back to cited text no. 8    
9.Ito Y, Kakau M, Kodama T et al: Intracranial high density epidermoid. No Shinkei Geka 1980; 8: 645-648.   Back to cited text no. 9    


Print this article  Email this article
Previous article Next article
Online since 20th March '04
Published by Wolters Kluwer - Medknow