Magnetic resonance and computed tomography imaging of a grade IV papillary endolymphatic sac tumour.

The endolymphatic sac tumour (ELST) is an adenomatous neoplasm of the papillary pattern originating from the endolymphatic sac's epithelium. We describe the computed tomography and magnetic resonance imaging features of a rare grade IV tumour with extensive skull base, cerebello-pontine and nasopharyngeal spread as well as involvement of the left temporomandibular joint. Papillary ELST may easily be misinterpreted on histopathological and even on immunohistochemical examination with other papillary lesions. Thus the radiological imaging features and localization in conjunction with histopathological features and clinical presentation play a paramount role in making the correct diagnosis.