Unruptured Intradiploic Dermoid Cyst with Incomplete Dermal Sinus overlying Torcular Haerophili in an Adult Woman: Uncommon Location for Uncommon Lesion

Dermoid Cysts are rare lesions, accounting for about 1% of intracranial neoplasms, that involve mainly pediatric population; among the etiopathogenetical hypotheses there is an abnormal entrapment of the cells of the epithelial ectoderm in the neuroectoderm at the time of the closing of the neural tube. We report a rare case of simptomatic Dermoid Cyst with incomplete dermal sinus, placed on posterior cranial fossa overlying Torcular Haerophili, in a 33 year old woman, which has been treated surgically. We highlight the particular onset area of the lesion, its rise not in pediatric but in adult age and the lack of adhesion between the lesion and the surrounding tissues, whereas it frequently occurs in intracranial Dermoid Cysts. We express besides the necessity of surgical therapy even in absence of acute symptomatology, due to the risk of rupture and/or infection typical of such lesions.