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Year : 2021  |  Volume : 69  |  Issue : 4  |  Page : 1091--1093

Recurrence of Symptoms on Long-Term Follow-up Following Subtotal Resection of Ruptured Intraventricular Dermoid

Ashutosh Kumar, Ved Prakash Maurya, Yashveer Singh, Sanjay Behari 
 Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

Correspondence Address:
Ved Prakash Maurya
C-Block (First Floor), Hospital Building, Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh - 226 014
India




How to cite this article:
Kumar A, Maurya VP, Singh Y, Behari S. Recurrence of Symptoms on Long-Term Follow-up Following Subtotal Resection of Ruptured Intraventricular Dermoid.Neurol India 2021;69:1091-1093


How to cite this URL:
Kumar A, Maurya VP, Singh Y, Behari S. Recurrence of Symptoms on Long-Term Follow-up Following Subtotal Resection of Ruptured Intraventricular Dermoid. Neurol India [serial online] 2021 [cited 2021 Dec 5 ];69:1091-1093
Available from: https://www.neurologyindia.com/text.asp?2021/69/4/1091/325383


Full Text



Sir,

Intracranial dermoid are rare benign tumors, while dermoids of intraventricular location are extremely rare. They remain asymptomatic or may present acutely following rupture. There is lack of consensus regarding optimal management of ruptured intraventricular dermoid, although adequate literatures are available regarding treatment of intracranial and spinal dermoid. We share the experience of recurrent symptom complex for nearly two decades following subtotal excision of intraventricular dermoid.

A 28-year-old gentleman was admitted following a seizure episode. After stabilization of this episode, his clinical examination was within normal limits. He was evaluated and his radiology was suggestive of midline lesion with extension into the ventricular cavity [Figure 1]. Eighteen years back, he presented with severe headache and multiple episodes of vomiting. He underwent endoscopic transcortical trans ventricular decompression of the dermoid. Intraoperatively, multiple bright coloured particles along with hairs were found disseminated within the ventricular cavity. The ventricular wall was thickened, highly vascular, and friable. A small portion of tumor was firmly adhered to the thalamostriate vein, this portion of the tumor was left in view of anticipated vascular injury. An external ventricular drain was placed, which later on; was converted to bilateral ventriculoperitoneal shunt. During the follow-up visits, the dispersed fat particles resulted in blockage of ventricular end which leads to shunt malfunction. He underwent shunt revision for three times, but in the absence of mass effect re-excision of tumor was not attempted. The anti-convulsant was continued in view of waxing waning course of the disease.{Figure 1}

During this admission, he underwent contrast-enhanced magnetic resonance imaging (CEMRI) brain which revealed a midline lesion causing distortion of the third ventricle with grossly asymmetrical lateral ventricles [Figure 2], [Figure 3], [Figure 4]. His anti-epileptic dosage was stepped up along with the steroids. There were no fresh seizure episodes, which leads to gradual improvement in sensorium. In view of widely disseminated disease, he was offered anti-epileptics and anti-edema measures with regular follow up.{Figure 2}{Figure 3}{Figure 4}

The dermoid cyst is formed as a result of abnormal non-disjunction of three layers of embryogenesis. The incidence of such a dermoid manifesting within the brain is very rare (0.04%-0.7%). The dermoids are circumscribed lesions with keratinized stratified squamous epithelial lining.[1],[2] The cystic contents are composed of sweat glands, apocrine glands, hair follicles as well as lipid cells in various combination. The accumulated secretions along with head movement and constant cerebral pulsations may possibly lead to rupture of dermoid cyst.[3] The dermoid cyst mostly holds the midline position and are noticed clinically as a consequence of capsular rupture. The enlarging size of the dermoid leads to mass effect over the adjacent neurovascular structures most commonly manifesting as obstructive hydrocephalus.[4] The asymptomatic period of dermoid ranges from 3 months to 7 years, if unruptured. Incidence of intracranial dermoid cyst undergoing rupture is 0.18%, and less than 16 cases of ruptured intraventricular dermoid cysts have been reported till date.[5]

The ruptured dermoid cyst manifest as altered mental status, seizure disorder, meningitis, focal neurological deficits and even sudden death. These ruptured dermoid disseminate in subarachnoid spaces and manifest as features of transient cerebral ischemia and psycho-organic syndrome.[6] The intense clinical symptom appears once chemical meningitis ensues. Ventriculitis, choroid plexitis and inflammation of ependymal lining contributes to the clinical picture. Occasionally, a smaller percentage of patients remain asymptomatic even after cystic rupture. Complete surgical excision is the ideal goal, though it may not be feasible due to adherence to critical neurovascular structures.

Computed Tomography (CT) scan of head is the initial imaging modality. The pathognomonic appearance of intracranial dermoid on CT have a characteristic fat density (-150 HU to 0 HU). The lesion appears hypodense with occasional calcified wall. The intraventricular dermoid appears as “air bubbles” in ventricles without contrast enhancement. The fat constituent of dermoid creates a “chemical shift artefact” due to mis registration of signal in frequency encoded direction.[7] Excellent differentiation between lipid, CSF and brain tissue can be achieved by using 3D- chemical shift selective gradient echo imaging with benefit of identifying even a very tiny amount of fat droplet floating freely in CSF or subarachnoid space.[8] No definite time limit is available in literature regarding resorption of fat droplets in subarachnoid space. The present case demonstrates several lipid globules even after 18 years following rupture of dermoid.

Surgical treatment of the dermoid involves complete microsurgical resection of the mass with the tumor wall. During excision, care must be taken to avoid spillage of tumor contents; else severe chemical meningitis ensues.[9] The basic treatment guidelines are to control the escalating intracranial pressure and mitigate the ongoing inflammation. Loading doses of steroids, in the form of dexamethasone, should be given as per body weight to tide over the acute crisis and urgent surgical decompression must be planned. The surgical bed must be copiously irrigated with medicated ringer lactate (with Gentamycin or Amikacin) till the effluent fluid turn out to be free from fat droplets. External ventricular drain should be inserted to prevent hydrocephalus in view of blocked CSF pathway.[10]

Majority of the fat droplets in the subarachnoid space, ventricles, and spinal canal behave inertly. Generally there is no direct correlation between extent of fat dispersion and severity of clinical symptoms. Communicating hydrocephalus occurs due to underlying aseptic meningitis or arachnoiditis. Reactive gliosis manifests as seizure episodes which are well controlled with anti-convulsant. Once the chemical meningitis sets in, intense enhancement along the ventricular ependyma and pial lining are noticed. These droplets need not to be removed, although; a close follow-up with MRI including DWI sequences at regular interval avoids complications in the form recurrent meningitis and hydrocephalus.

 Learning Points



The persistence of symptoms should raise the possibility of residual tumor or regrowth of the residual tumor.In case of ruptured intracranial dermoid, regular follow up with imaging precludes the aggravation of clinical symptoms.Complete yet safe surgical excision should be attempted in all cases of dermoid tumor to abort the prolonged and protracted course.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his names and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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