Suprasellar dermoid cyst masquerading as tumor: A case report

Intracranial dermoid cysts (DCs) are well-defined, rare ectodermal inclusion cystic lesions. Symptomatic DCs usually present with symptoms due to local mass effect, seizures, or recurrent meningitis, depending on the specific location of the lesion. Suprasellar DCs have fairly classical features and locations, allowing radiological diagnosis in most patients; however, they can sometimes mimic some tumors in the region. Despite the progress made in imaging modalities, it can still be difficult to exclude the differential diagnosis of other tumors. In this report, we present an interesting case of an atypical DC that mimicked a tumor, specifically a craniopharyngioma or meningioma. A 60-year-old female presented with headaches for four months and left visual field defects. A cranial computed tomography (CT) scan revealed an iso-to-hyperdense suprasellar lesion with intralesional calcification, which was extended to the left parasellar region. Brain magnetic resonance imaging (MRI) showed a suprasellar and more in the left sphenoid lesion that was hyperintense on T1-weighted imaging (T1WI) and hyper to mixed signal on T2-weighted imaging (T2WI), with gadolinium enhancement. Sphenoid wing meningioma and craniopharyngioma were mainly suspected as differential diagnoses. Intraoperatively, fluid was evacuated, and it was like machine oil. It was very comparable to the typical fluid of craniopharyngioma. Consequently, part of the lesion wall was dissected and portions of fatty and calcified content were removed. While removing the deepest part of the lesion, we encountered several hair follicles within the lesion. Immediately, the diagnosis shifted into a DC. Histopathology confirmed the diagnosis. The DCs can be considered in the differential diagnosis of suprasellar tumors, as they can have similar clinical and radiological features to more commonly encountered tumors such as craniopharyngiomas and meningiomas, particularly when located in the suprasellar region and presenting with imaging characteristics that are non-cystic and not hypodense.