Low-grade adenocarcinoma of endolymphatic sac origin

We present a case of papillary cystic low-grade adenocarcinoma of endolymphatic sac origin. These tumors are very rare and only a few cases have been reported in literature. They have a protracted clinical course causing progressive invasion and bony destruction. Radiologically, they appear as a heterogenous lobulated vascular mass, invading bone and compressing surrounding structures. Histologically, these tumors are composed of uniform population of cells, resembling normal endolymphatic sac epithelium. This causes considerable diagnostic difficulty. A strong index of suspicion along with clinical and radiological correlation is essential to arrive at a correct diagnosis. In some bilateral cases, association with von Hippel–Lindau disease has been noted. Radical mastoidectomy and temporal bone resection, which may sometimes necessitate sacrifice of cranial nerves, is the treatment of choice.