Intracranial dermoid cyst ruptured into the membranous labyrinth causing sudden sensorineural hearing loss: CT and MR imaging findings

Focal traumatic rupture of a dermoid cyst in a pediatric patient: case report and literature review

BACKGROUND

Dermoid cysts are rare congenital teratomas that can occasionally rupture and cause chemical meningitis, neurological deficit, or hydrocephalus. Rarely, dermoid cysts in the pediatric population can rupture spontaneously and even more rarely rupture due to trauma. To date, there are only five documented cases of traumatic rupture of a dermoid cyst. A 2-year-old male presented with 5 days of left eye ptosis and ophthalmoplegia after suffering a fall and was found to have a ruptured left anterior clinoid dermoid cyst that was surgically resected. The patient had significant improvement postoperatively.

SIGNIFICANCE

To the authors' knowledge, this is the first reported case in the literature of a ruptured dermoid cyst after trauma in a pediatric patient and the first case of a traumatically ruptured dermoid cyst presenting with neurological deficit.

Dermoid Cyst of the Prepontine Cistern and Meckel's Cave: Illustrative Case and Systematic Review

Objective  Dermoid cysts are benign, congenital malformations that account for ∼0.5% of intracranial neoplasms. The authors describe a 42-year-old female with a prepontine dermoid cyst who underwent apparent gross total resection (GTR) but experienced cyst recurrence. To date, very few cases of prepontine dermoid cysts have been reported. The prevalent region where these cysts are located can be difficult to determine. In addition, the authors systematically review the literature to characterize the clinical presentation, anatomical distribution, and surgical outcomes of intracranial dermoid cysts. Design  Systematic review. Setting/Participants  PubMed, Web of Science, and Scopus databases. Main Outcome Measures  Extent of resection, symptom improvement, and recurrence rates. Results  A total of 69 patients with intracranial dermoid cysts were identified. Three (4.3%) intracranial dermoid cysts were located in the prepontine cistern. The average age of patients was 33.3 years. The most common presenting symptoms were headache (52.2%) and visual disturbances (33.3%). Intracranial dermoid cysts were distributed similarly throughout the anterior, middle, and posterior cranial fossae (29.0%, 36.2%, and 29.0%, respectively). GTR was achieved in 42.0% of cases. Thirty-four (49.3%) patients experienced symptom resolution. Recurrence rate was 5.8% at a mean follow-up of 2.1 years. Conclusions  Intracranial dermoid cysts most often present as headaches and visual disturbances. Intracranial dermoid cysts were found in the anterior, middle, and posterior cranial fossae at similar frequencies but with clear predilections for the Sylvian fissure, sellar region, and cerebellar vermis. Outcomes following surgical excision of intracranial dermoid cysts are generally favorable despite moderate rates of GTR.

Abnormal Magnetic Resonance Imaging Findings in Patients With Sudden Sensorineural Hearing Loss: Vestibular Schwannoma as the Most Common Cause of MRI Abnormality

The etiology of sudden sensorineural hearing loss (SSNHL) remains unclear in most cases. This study aimed to assess abnormal magnetic resonance imaging (MRI) findings in patients with SSNHL and evaluate the value of MRI in identifying the cause of SSNHL.A retrospective analysis of the charts and MRI findings of 291 patients with SSNHL was performed.In 291 patients, MRI abnormality, which was considered a cause of SSNHL, was detected in 13 patients. Vestibular schwannoma involving the internal auditory canal (IAC) and/or cerebellopontine angle was observed in 9 patients. All 9 patients had intrameatal tumors, and 6 of the 9 patients displayed extrameatal extension of their tumors. The tumor was small (<1 cm) or medium-sized (1.1-2.9 cm) in these 6 patients. Intralabyrinthine schwannoma, labyrinthine hemorrhage, IAC metastasis, and a ruptured dermoid cyst were each observed in 1 patient.The most commonly observed MRI abnormality in patients with SSNHL was vestibular schwannoma, and all of the lesions were small or medium-sized tumors involving the IAC.