Radiolucent intracranial dermoid Cyst. Report of an unusual case

Dermoid cyst, unusual location of the pterion: About a case and review of literature

Intracranial dermoid cysts are benign tumors of congenital origin. The intradiploic forms are rare, exceptional at the pterional level. We report the case of a 10-year-old girl who presented with a cutaneous fistula in the left frontotemporal region. The blind end of the fistula was an intradiploic dermoid cyst in the rare location of the pterion confirmed by imaging and histopathology. Once this lesion is suspected, it is important to identify its location and morphology using imaging techniques and to complete excision of the cyst to avoid complications associated with infection and to mitigate the risk of subtotal resection.

An Intracranial Extradural Dermoid Cyst Presenting with Two Dermal Sinuses and an Abscess in a Child

Dermoid cysts account for only a small fraction of intracranial masses, with extradural dermoid cysts being considered a much rarer entity than those located intradurally. Intracranial dermoid cysts vary in clinical presentations: some maybe asymptomatic whilst others harbor features of raised intracranial pressure, neurological deficits, or even aseptic meningitis. Dermoid cysts may also present with cutaneous lesions. Herein, we report a rare case of a 1-year-old female presenting with a midline, scalp abscess. Brain MRI revealed an intracranial, extradural tumor, with features suggestive of a dermoid cyst, unusually located in the crista galli, and complicated by the formation of two cutaneous sinus tracts. After identification and characterization by MRI, bitemporal craniotomy was performed with complete excision of the mass and sinus tracts. Histological analysis confirmed dermoid cyst as the final diagnosis. Postoperatively, the patient recovered fully and had no evidence of recurrence in subsequent visits. The case mentioned above highlights the rarity of such a presentation for an intracranial extradural dermoid cyst and the vitality of early imaging for midline cutaneous lesions for identification of intracranial extensions and avoidance of detrimental consequences.

Craniocerebral epidermoids and dermoids. A review of 44 cases

We review 40 epidermoids and 4 dermoids of the skull and brain treated surgically in our Department between 1976 and 1987. Fourteen were extradural and 30 intradural. The mean duration of symptoms was 3 years for extradural and 10 years for intradural tumours. Symptoms varied with tumour site, in some sites being helpful in differential diagnosis. Skull X-rays and CT were the key diagnostic investigations in extradural and CT in intradural lesions, the latter, with few exceptions, presenting a characteristic CT scan. In 7 cases MRI supplied important details on the tumour boundaries. All the diploic and orbital lesions were removed totally, with a good outcome. Twelve of the intradural lesions were removed totally, 9 subtotally and 9 partially, with a good outcome in 21 patients and a poor outcome in 4; 5 patients died. Outcome was unrelated to degree of removal.

Dense suprasellar epidermoid cyst. A case report

A case of a dense epidermoid cyst of the suprasellar cistern is presented. The clinical symptoms were headache radiating to the left eye and a quadrant anopsia on the left eye. The density of the epidermoid was 62 HU and no significant contrast enhancement occurred after contrast application. The main feature which allows differentiation from other hyperdense suprasellar lesions seems to be the lack of contrast enhancement.

Diagnosis by computerized tomography of intradural dermoid with spontaneous rupture of the cyst

Two cases of para- and suprasellar dermoid cysts are presented. The specific CT findings for this tumour are demonstrated: very low absorption values below minus 40 EMI units, variable densities in the cyst content, shell-like annular calcifications, and absent central enhancement effect. Spontaneous perforation of the cyst with dissemination of dermoid material into the CSF spaces is shown. The differential diagnosis from other low density lesions (epidermoid, cystic craniopharyngioma, arachnoid cyst) is discussed.

Low-attenuation lesions in the middle cranial fossa: differential diagnosis

The reliability of cranial computed tomography (CT) in detecting a broad range of intracerebral disorders has been well established (1) and its complementary role with other neuroradiologic procedures has been documented (2). Some attempts at inferring specific histologic diagnosis from static CT scans have been made (3,4). However, other investigators have demonstrated that it is difficult to separate cystic from noncystic, benign from malignant, and neoplastic from non-neoplastic lesions by absorption coefficients alone (5,6). While initial studies utilizing dynamic CT scanning indicate that patterns of contrast accumulation may be helpful in distinguishing enhancing cerebral lesions (7,16), the differential diagnosis of the low-attenuation lesion remains difficult (17). We present a series of hypodense lesions in the middle cranial fossa that demonstrate a broad range of pathologic entities. Their CT features, differential diagnosis, and pathologic correlation are discussed.

Floating Myodil--a new sign of fat in the ventricles

A case in which a remarkable series of CT studies demonstrated a dermoid cyst is reported. There was leakage of fat into the ventricular system which caused hydrocephalus due to adhesions partly obstructing the fourth ventricular outlets. The latter was confirmed by a ventriculogram using Myodil which dissolved in, or combined with, the fat produced by the tumour. This resulted in a high attenuation substance of lower specific gravity than CSF, which appeared to cause acute ventriculitis.