Retrolabyrinthine surgery: anatomy and pathology

Retrolabyrinthine surgery is done to expose the cerebellopontine angle directly through the ear. It is indicated when the hearing in the ear to be operated upon is useful. The surgical technique entails four steps: complete mastoidectomy, extended posterior exposure of the sigmoid sinus, exposure of the posterior fossa dura, and exposure of the cerebellopontine angle. Retrolabyrinthine exposure of the cerebellopontine angle is indicated in tic douloureux, atypical facial pain, and hemifacial spasm. Recently, this approach has been used for sectioning the vestibular nerve, exploration of the posterior fossa to obtain a diagnosis, subtotal resection of large cerebellopontine angle tumors, and for the treatment of other cranial nerve problems. The histopathologic findings in the temporal bones of two patients who underwent retrolabyrinthine removal of cerebellopontine angle masses were reviewed. In one, subtotal resection of an acoustic tumor was attempted to preserve hearing in the presence of a bilateral tumor, with no adverse effect on the middle or inner ear. In the second, retrolabyrinthine exploration of the cerebellopontine angle was done for primary cholesteatoma, and operative injury to the nonampullated end of the posterior semicircular canal was noted. Retrolabyrinthine subtotal resection of large acoustic tumors is advocated in bilateral cases and in elderly persons to delay the inevitable loss of hearing by decompression and partial removal of the tumor mass. In primary cholesteatoma of the cerebellopontine exploration may be indicated to obtain a definitive diagnosis before surgical extirpation of the disease is planned.     

Charcot-Leyden crystals: pathology and diagnostic utility

Eosinophilia is associated with several diseases of the upper respiratory tract. The predominance of eosinophils in nasal tissue, secretions, and lavage fluid has been used as an aid in the diagnosis of allergic rhinitis. Charcot-Leyden crystals, considered to be a morphologic hallmark of eosinophil-related disease, are often also found in inflamed nasal tissue and paranasal sinus contents of patients with allergic rhinitis. These bipyramidal-shaped crystals are composed of the enzyme lysolecithin acylhydrolase, one of several eosinophilic proteins that damage respiratory epithelium and contribute to the pathology of allergy in the upper respiratory tract.     

Viral labyrinthitis: early pathology in the human

The histologic findings in the temporal bones of three patients who died from viral encephalopathy are presented. Pathology was restricted to the scala media, vestibular labyrinth, and internal auditory canal and was considered to be expressions of viral labyrinthitis. The changes were different degrees of degeneration of the organ of Corti, early encapsulation of the tectorial membrane, degeneration of the stria vascularis, and round cell infiltration of the modiolus and contents of the internal auditory canal. A new finding in the organ of Corti and early stages of cystic degeneration of the stria vascularis are documented. In all cases, the saccule was degenerated with sloughing of the otolithic membrane and vestibular labyrinth was involved in varying degrees.     

Posterior glottic pathology

In infants and children, pathology in the posterior glottis is usually congenital or acquired due to endotracheal intubation. Diagnostic errors and omissions are less likely to occur with an anaesthetic technique where no endotracheal tube is used, where the posterior commissure and arytenoids are deliberately separated by a laryngoscope and where movements of the vocal cords and arytenoids are carefully assessed.     

Paragangliomas: classification, pathology, and differential diagnosis

This article discusses the paraganglion system and extra-adrenal paragangliomas. In particular, the clinicopathologic, immunohistochemical, and ultrastructural features of paragangliomas and neuroendocrine neoplasms of the larynx are presented with a discussion of the differential diagnosis.     

Botryoid rhabdomyosarcoma of the nose: pitfalls of pathology

A 2-year-old Swiss boy was referred to our hospital because of an obstructive sleep apnea syndrome with suspected recurrent choanal polyp. During surgery, a polypoid soft mass was found in the right nose and extirpated. The histology of the resected polypoid tumor seemed compatible with a polyp; however, immunohistochemistry revealed a botryoid rhabdomyosarcoma. Rhabdomyosarcomas are rare. The most important differential diagnoses for rhabdomyosarcoma are discussed and methods available for differentiating are included.     

Cisplatin-induced ototoxicity: audiometric findings and experimental cochlear pathology

Twenty-four (48%) out of a group of 50 patients treated with one to three single doses of cisplatin compound (cis-DDP), at a dosage of 60 mg/m2 body surface, were found to have deterioration of post-treatment pure tone audiometric threshold levels. Statistical analysis of pre- and post-treatment hearing losses by means of the paired t-test, however, did not show any significant hearing loss associated with cis-DDP-toxicity, nor could hearing loss following treatment be correlated to ages of the patients, pre-treatment hearing impairments, specific frequencies, or the number of treatment courses given. In contrast, cochlear damage was studied in the guinea pig model by daily administration of high cumulative doses of cis-DDP, and was found to be dose-dependent and selectively restricted to the outer hair cells of the inner ear and corresponding nerve fibers. Hair cell degeneration was most severe in the basal turn of the cochlea, and progressed in an apical direction so that the cells in the first row were the most affected.