A Rare Case of Endolymphatic Sac Tumour: Clinical, Radiological, Pathological and Immunohistochemical Findings with Review of Literature.

Endolymphatic sac tumour (ELST) is a rare low grade malignant epithelial tumour of the petrous temporal bone, thought to arise from papillary epithelium of the endolymphatic sac. They may occur sporadically or in association with Von-Hippel Lindau disease. ELST is extremely rare neoplasm with benign histopathological appearance and clinically destructive behaviour. Because of the rarity of this tumour, it can easily be confused with other tumours such as paraganglioma, middle ear adenoma, metastatic carcinomas or choroid plexus papilloma. We report here a rare case of ELST with review of literature and discuss the differentiating features of ELST from its mimickers, showing a papillary configuration.