Intracranial mature teratomas in the posterior fossa: a rare presentation in the cerebellopontine angle during adulthood

Background Intracranial teratomas are rare tumors of the central nervous system (CNS). Their occurrence in the posterior fossa is particularly uncommon in adults, with only three previously reported cases in the cerebellopontine (CP) angle, all in women and located in the right cistern. Case presentation We present the case of a 51-year-old male patient with left-sided hearing loss, diplopia, and balance disturbances. Magnetic resonance imaging (MRI) revealed a large extra-axial mass in the left CP angle compressing the left cerebellar hemisphere and brainstem. An epidermoid cyst was suspected initially. The patient underwent surgical treatment, and histopathological analysis revealed mature teratoma. Conclusion Posterior fossa mature teratomas, though extremely rare in adults, should be considered in the differential diagnosis of large CP angle masses, especially - but not exclusively - when MRI findings are “atypical”. Complete surgical resection and continuous follow-up are essential to prevent malignant transformation and to monitor recurrence.