![]() ![]() The decision should be based on the functional status of the cranial nerves, for which reliable electrophysiological monitoring is indispensable. ![]() In view of the nonneoplastic characteristic of these lesions, a more conservative approach is justified. Intraoperative surgical findings of tumor infiltration of the faciocochlear cranial nerve complex may support simple observation. Accurate preoperative diagnosis by radiological means is not possible, but careful evaluation of the different signal intensities on magnetic resonance imaging studies may indicate this rare pathological condition. Symptoms and signs of internal auditory canal hamartomas are congruent with other typical pathological lesions of the internal auditory canal and cerebellopontine angle. Therefore, a radical tumor removal was performed that sacrificed the cochlear but preserved the facial nerve. In Patient 2, minimal tumor dissection resulted in complete loss of auditory brainstem response without reversibility. ![]() In Patient 1, after nerve decompression by subtotal tumor removal, preserved auditory brainstem responses and facial nerve electromyography indicated functional nerve preservation and facilitated the decision for partial resection. In view of the unclear intraoperative histology, surgical management was based on criteria of cranial nerve function. The lesions were exposed via a suboccipital transmeatal approach, and tumor infiltration of the cochlear and/or facial cranial nerves was identified. PMID: 2395403 DOI: 10.1288/00005537-199009000-00007 Abstract Unilateral acoustic neuromas in only-hearing ears and bilateral acoustic neuromas (NF-2) are separate entities, but both pose a common problem because surgical removal has the potential to leave the patient totally deafened. Two patients presented with clinical findings typical of vestibular schwannomas, i.e., tinnitus, hearing loss of 30 dB, and an intrameatal contrast-enhancing lesion on magnetic resonance imaging studies. The right proximal IAC showed significant stenosis to 2 mm in the AP dimension, and the left IAC showed stenosis to 5 mm ( Fig. 1 ).To highlight the clinical, radiological, and surgical findings and therapeutic options for this rare entity, which may mimic a purely intrameatal vestibular schwannoma, and to define the particular aspects of preoperative differential diagnosis and surgical management. High-resolution computed tomography of the temporal bone revealed prominent bony osteomas along the cerebellopontine angle cisterns and porus acusticus bilaterally, right greater than left. These secondary causes of IAC stenosis should be distinguished from primary causes such as hyperostotic thickening of the medial temporal bone from pathologies including Paget’s disease, fibrous dysplasia, or osteopetrosis.Ī 38-year-old woman presented with a one-year history of progressive, bilateral sensorineural hearing loss and tinnitus (L > R), otalgia, and vertigo. Definitive distinction between osteomas and exostoses is by histopathology. In contrast, exostoses are smooth and broad-based, and are more likely to be bilateral. Radiologically, osteomas may be distinguished from exostoses by the presence of bone marrow as well as an acute protrusion into the IAC space. However, patients may be asymptomatic with the lesions only incidentally discovered on radiograph or upon autopsy. Associated symptoms include hearing loss, vestibular dysfunction, tinnitus, and facial spasms. Twenty one cases of osteomas and exostoses of the IAC have been reported with only six cases demonstrating bilaterally. Rarely, they are found in the internal auditory canal (IAC). When present, they are most commonly found in the calvarium, facial bones, and mandible. Osteomas and exostoses are benign tumors of bone with an estimated prevalence of 0.42%. The identification of the vestibular nerves can be facilitated by the decompression internal auditory canal laterally, in order to locate definitely. ![]() In this report, we review the literature on bony lesions of the IAC and present two cases: one case of bilateral compressive osteomas and one case of bilateral compressive exostoses of the IAC. Osteomas and exostoses are benign tumors of the bone that occur in the head and neck region but are rarely found within the internal auditory canal (IAC). ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |