Posterior fossa ruptured dermoid cyst presenting with hydrocephalus

Dermoid cysts are rare, benign lesions of embryological origin that represent 0.1-0.7% of all intracranial tumors. They are mainly located in the supra tentorial space, especially in the parasellar region. Their location in the posterior fossa remains uncommon. Rupture of intracranial dermoid cysts is a rare phenomenon. We present a case of dermoid cyst, which had ruptured into ventricular system. Computed Tomography and MRI revealed fat in the fourth ventricle, prepontine cistern, and cerebellomedullary cistern. Hydrocephalus was noted. We performed right ventriculo-peritoneal shunt on which patient improved and he continues to remain asymptomatic one year after.