DEAFNESS DUE TO BILATERAL ENDOLYMPHATIC SAC TUMORS IN A CASE OF VON-HIPPEL-LINDAU SYNDROME

A case of bilateral endolymphatic sac tumours is reported. In a patien t with von Hippel-Lindau syndrome, tumour growth in the right cerebell opontine angle caused deafness. The tumour was removed and classified as a metastasis from a thyroid carcinoma. However, on thyroidectomy no primary neoplasm could be found. Eight years later a similar tumour w as operated on in the left petrosal bone. Histological appearance, imm unocytochemical findings, and the clinical context gave evidence that the tumours had to be reclassified as endolymphatic sac tumours-extrem ely rare entities. The report supports the hypothesis, suggested by th e few earlier case reports, that endolymphatic sac tumours could be on e of the inherent tumour manifestations in von Hippel-Lindau syndrome.