Lipoma of the cerebellopontine angle - a case report

Background: Lipomas of the cerebellopontine angle are rare. Until today in the english literature only isolated cases are described. The most frequent symptoms are: hearing loss (62,2%), vertigo (43,3 %) and tinnitus (42,2 %). With the help of MRI intracranial lipomas can be diagnosed almost certainly. Patient: A 26 year old patient presented himself to our outpatient departement with recurrent vertigo and tinnitus since two months. Electronystagmography and caloric testing showed a unilateral weakness of the right vestibular organ. Audiometric examination revealed a Normacusis on the right side. BERA resulted in borderline prolonged interpeaklatency on the right side, wave IN. MRI showed a ca. 5x8x11 mm Lipoma of the right cerebellopontine angel which surrounded the vestibulocochlear nerve. In contrast to schwannomas which are often described in this area the lesion did not enhance contrast medium. On the native T1 sequence the tumor was hyperintense and fat-supression images confirmed the tumor to be fat in origin. Because of the minor symptoms and the small size of the tumor we recommended a BERA after six months and an MRI every year. Conclusion: The therapeutic options of a lipoma of the cerebellopontine angel depend on the clinical symptoms and a radiologic confirmed progression of size. Because of the received data until today an operative therapy is only indicated when symptoms clinically can not be treated or the leason seems to be a well differentiated liposarcoma.