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Case Series | | Volume 1 Issue 3 (October-December, 2011) | Pages 95 - 99

Epidermoid Cysts in the Frontal Lobe – A Case Series

 ,
 ,
1
Department of Surgery, Jinnah Post-graduate Medical Center, Karachi, Pakistan
2
Section of Neurosurgery, Department of Surgery, Aga Khan University, Stadium Road, Karachi, Pakistan
3
Pakar Neurosurgery, Hospital Sultanah Aminah, Johor Bahru, Malaysia
Under a Creative Commons license
Open Access
Received
July 7, 2011
Accepted
Aug. 3, 2011
Published
Dec. 30, 2011

Abstract

BACKGROUND: Intracranial epidermoid tumors account for approximately 1% of the intracranial tumors. These tumors are thought to arise from displaced epithelial remnants after the neural tube closure. These tumors are usually benign intradural but extracerebral lesions and are rarely found within the substance of the brain. Even more rare location for epidermoid tumors is fronto-ethmoidal. To the best of our knowledge, only 28 cases have been reported in this location so far.

 CASES: Here we report two cases of middle-aged men presenting with recurrent headaches, which were associated with behavioral changes and seizures. Both men were diagnosed with fronto-ethmoidal epidermoid cysts, which were surgically excised. Surgical excision was easily established due to the avascular nature of the tumor. However, the tumor capsules had to be left behind due to adhesions with vital structures. On follow-up visits, the patients were asymptomatic and were living without any residual symptoms.

CONCLUSION: Surgical resection appears to be the mainstay of treatment; however, the extent of resection is dictated by adherence of the tumor capsule to the surrounding vital structures. The advantages of aggressive neurosurgical intervention must be weighed against an acceptable risk of neurological complications.  Given the indolent growth pattern, subtotal resection is also acceptable.

 

Keywords
Epidermoid Cyst; Frontal Lobe; Case Series

INTRODUCTION

Intracranial epidermoid tumors first described by Bailey[1] and Cushing[2] in the early 1920s, account for nearly 1% of the intracranial tumors.[3-5] Thought to arise from displaced epithelial remnants that remain after the neural tube closure, these tumors are usually congenital; however, acquired lesions are rarely reported.[46] These are usually benign intradural but extracerebral lesions and are rarely found within the substance of the brain. Furthermore, fronto-ethmoidal location of epidermoid is rare. Our review of the Medline and Google Scholar databases revealed 28 reported cases. Here we report two cases of frontal lobe epidermoid tumors with specific emphasis on pre-operative radiological features and operative findings.

CASE SUMMARIES

Case-1

A thirty-year old male presented in the outpatient clinic with complaints of progressively worsening headaches for the past 5 months. The headaches were mild to moderate in intensity and were worse early in the morning. Headaches improved with over-the-counter analgesics. The headaches were also associated with nausea, retching and behavioral changes (mainly forgetfulness). There was no history of seizures, fever, or visual disturbances. His neurological examination was essentially unremarkable, except that his Mini-Mental State (MMS) examination revealed a score of 23 out of 30. The patient had previously undergone Magnetic Resonance Imaging (MRI), which revealed a mass lesion of about 7.5 x 6.0 x 5.5 cm in dimension, located at the right frontal lobe along the anterior part of falx cerebri. The lesion was producing homogenous hypointense signals on T1-weighted images, while it produced heterogeneous bright signals on T2-weighted images. There was no post-gadolinium enhancement of the lesion [Figure 1]. The above findings were suggestive of an epidermoid cyst. The patient underwent a right frontal craniotomy. After opening the dura, a pearly white mass was found with a well-demarcated interface with cerebral surface. The mass was avascular and was easily excised by a suction catheter. A near-total excision was achieved but the capsular membrane had to be left behind as it was adherent to the surrounding cerebral tissue. Histopathological examination of the excised tissue confirmed the diagnosis of epidermoid cyst with keratinous crystals. The patient’s post-operative recovery was un-eventful and he was discharged on the 7th post-operative day. On follow-up, the patient claimed a remarkable subjective improvement. His headaches had also resolved. At his 6-month follow-up visit, his MMS examination revealed a score of 26/30.

Case-2

A twenty-year old male presented to our emergency department with generalized tonic clonic seizures associated with loss of consciousness, frothy discharge from mouth and urinary incontinence. There was no history of fever, visual disturbances or trauma. On examination, he was drowsy but arousable with a Glasgow Coma Scale (GCS) of 13/15. There were no other neurological deficits and the systemic examination was within normal limits. As per hospital protocol, he was started on intravenous phenytoin. A careful review of the patient’s history revealed that he had complained of mild headaches, which were relieved by over-the-counter analgesics. Computerized Tomography (CT) scan showed a cystic midline lesion extending into the anterior fronto-basal regions bilaterally. The walls of the lesion were hyperdense on the right side. There was no post-contrast enhancement on the CT scan [Figure-2]. MRI revealed a 4.5 x 2.5 x 3.0 cm lesion, which was hypointense on T1-weighted sequences and hyperintense on T2-weighted sequences. There was no post-contrast enhancement [Figure 3].These features were suggestive of an epidermoid cyst. After 48 hours, the patient was clinically stable and underwent a bifrontal craniotomy. The mass was filled with pearly white material and was easily removed using a suction catheter. Due to the avascular nature of the mass, it was possible to achieve near-total excision, leaving only the adherent membranous lining behind. His post-operative recovery was uneventful. Histopathological examination confirmed the diagnosis of an epidermoid cyst. At 3-month follow up, the patient had no complaints and his seizures were well controlled on a maintenance dose of phenytoin.