Extradural Dermoid Cyst of the Anterior Infratemporal Fossa. Case Report

Dermoid cyst of the infratemporal fossa: a case report of surgical resection by infratemporal fossa type B approach

OBJECTIVE

This is a case report of a dermoid cyst located in the infratemporal fossa and its surgical removal using infratemporal fossa type B approach.

CASE REPORT

A 15-year-old male was referred from a local clinic after an incidental finding of a mass lesion in the skull base area on computed tomography (CT). Pre-operative magnetic resonance imaging showed a large cystic mass lesion, expanding to the foramen ovale with fat component in the right infratemporal fossa region. The lesion was completely excised using an infratemporal fossa type B approach.

CONCLUSION

An extremely rare case of dermoid cysts of the infratemporal fossa was managed with infratemporal fossa type B approach without severe complication.

Frontotemporal giant extradural dermoid cyst: illustrative case

BACKGROUND

Dermoid cyst is a rare benign tumor exhibiting a typical radiological pattern and most commonly located along the midline. Laboratory examination was always normal. However, the features of some rare cases are atypical that can be easily misdiagnosed as other tumors.

OBSERVATIONS

A 58-year-old patient presented with tinnitus, dizziness, blurred vision, and gait unsteadiness. Laboratory examination showed the serum levels of carbohydrate antigen 19-9 (CA19-9) were significantly increased (186 U/mL). A computed tomography (CT) scan revealed a predominant hypodense lesion in the left frontotemporal region with a hyperdense mural nodule. The lesion appeared as an intracranial extradural mass with a mural nodule on the sagittal image, displaying mixed signal on T1- and T2-weighted imaging. A left frontotemporal craniotomy was performed for cyst resection. Histological results confirmed a diagnosis of dermoid cyst. No tumor recurrences were observed at the 9-month follow-up.

LESSONS

Extradural dermoid cyst with a mural nodule is extremely rare. When a hypodense lesion on CT shows mixed signal on T1- and T2-weighted imaging with a mural nodule, even if it is located in the extradural areas, it is important to consider a dermoid cyst. Serum CA19-9 combined with atypical imaging features may contribute to the diagnosis of dermoid cysts. Only recognition of atypical radiological features can avoid misdiagnosis.

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.

Endoscopic Transnasal Transpterygoid Excision of an Infratemporal Dermoid Cyst

OBJECTIVE

Intracranial dermoid cysts are rare, slow-growing masses of sellar, parasellar regions, and posterior cranial fossa. The symptomatology of these cysts depends on the localization and presence of rupture. The preoperative diagnosis of these cysts by imagining techniques is distinctive as they have characteristic appearances.

PATIENT

Endoscopic transnasal transpterygoid approach to infratemporal fossa for an extradural dermoid cyst of a 24 year-old woman is presented in this clinical report. Headache, dizziness, and retro orbital pain were her main complaints and diagnostic imagining studies designated an intracranial dermoid cyst preoperatively. The cyst was excised uneventfully with no recurrence 6 months after the operation.

CONCLUSION

Surgery of intracranial lesions neighboring critical vital neurovascular structures can be challenging to the surgeon. Alternative minimal invasive approaches should always be considered for averting life-threatening complications.