Name : Morteza
Family :Sanei Taheri
Affiliation : ----------------
Academic Degree: ----------------
Resident : Samira Shahhamzei
Gender : Male
Age : 22
Head & Neck Imaging
A 22 Y/O man with vertigo
Imaging Procedures and Findings
CT scan shows a destructive lesion involving retrolabyrinthine bone with extension to inner ear . intra tumoral calcification is noted . T1-weighted and T2-weighted images demonstrate heterogeneous mass with enhancement , petrous bone destruction, and obliteration of the internal auditory canal. T2WI clearly depicts tumor extension to inner ear with mass effect on labyrinth and vestibule swelling .
The endolymphatic sac lies between the petrous periosteum and the posterior fossa dura, near the sigmoid sinus and jugular bulb, and posterior to the internal auditory canal. Its putative function is to regulate endolymphatic pressure, fluid volume, and ionic balance within the inner ear. Endolymphatic sac tumors are histologically benign but invasive tumors that arise from the endolymphatic duct or sac and are located in the posterior petrous bone. Because of their invasive nature, ELSTs frequently cause hearing loss (often sudden and significant), tinnitus, vertigo, aural fullness, and facial nerve dysfunction .Although they can occur sporadically, ELSTs recently have been associated with VHL disease.When identified in patients with VHL disease, ELSTs often occur bilaterally and result in significant neurological disability, including deafness and disequilibrium. CT findings in patients with ELST include retrolabyrinthine bone destruction between the fundus of the internal auditory canal and the sigmoid sinus. Irregular bone margins are characteristic of destruction; also, intratumoral bone is evident in many cases. MRI typically reveals a heterogenous mass with hypo-, hyper-, and isointense foci on T1- and T2-weighting and variable enhancement with contrast.
Endolymphatic sac papillary tumor
1. Lo WW, Applegate LJ, Carberry JN, et al. Endolymphatic sac tumors: Radiologic appearance. Radiology 1993;189:199-204. 2. H. Jeffrey Kim, John A. Butman, , Carmen Brewer, et al. Tumor of the Endolymphatic Sac in Patients With Von Hippel-Lindau Disease: Implications for Their Natural History, Diagnosis, and Treatment. Neurosurg Focus. 2005;19(2)