Histopathology of the facial nerve after longitudinal temporal bone fracture

The temporal bone histopathology in a patient who suffered repeated head trauma and a longitudinal temporal bone fracture shows unusual features associated with the facial nerve. In the distal meatal segment, a type of traumatic neuroma was found with disorganized nerve bundles and distinct areas of Schwann's cell proliferation but lacking fibrosis. Periosteal new bone formation in the labyrinthine segment narrows the fallopian canal and protrudes into the nerve, which completely fills the canal. The tympanic and mastoid segments of the nerve show severe degeneration of nerve fibers and an increase in connective tissue between fascicles. An attempted facial nerve decompression did not reach the area of primary pathology in the labyrinthine and meatal segments of the nerve, which could have been exposed by the transtemporal supralabyrinthine approach.     

The cochlear aqueduct in pediatric temporal bones

The cochlear aqueduct is a bony channel which contains the fibrous periotic duct and connects the perilymphatic space of the basal turn of the cochlea with the subarachnoid space of the posterior cranial cavity. Previous histological studies suggested that patency depended on age, whereas a more recent study showed no statistical correlation between age and patency. To clarify patency in pediatric cochlear aqueducts, we selected 21 temporal bones from 12 infants and children, varying in age from birth to 9 years, in which the cochlear aqueduct was fully visible on one histological section. Photographs were taken for documentation and the length and width of the orifice of the external aperture of the aqueduct at the scala tympani were measured and followed to the internal aperture at the subarachnoid space. The lumen of the duct was examined for mononucleated cells, blood cells and fibrous tissue. Measurements revealed that the mean length of the cochlear aqueduct was 4.6 mm (range, 2.4–10.7 mm), mean width of the external aperture was 484 μm (range, 225–869 μm), and mean width of the internal aperture was 1293 μm (range, 699–2344 μm). The mean diameter of the narrowest part (isthmus) was 151 μm (range, 75–244 μm). In all temporal bones the cochlear aqueduct was patent, with one exception. This latter temporal bone was from a 2-month-old girl with multiple intralabyrinthine anomalies, with the missing cochlear aqueduct believed to be due to an aplasia. Our results support prior measurements of the cochlear aqueduct and demonstrate a short and patent cochlear aqueduct in newborns. With growth, a significant increasing length of the duct was found.     

The utriculo-endolymphatic valve in pediatric temporal bones

The utriculo-endolymphatic valve (UEV) is located in the posterior wall of the utricle at its junction with the utricular duct and was first described in a human fetus by Bast in 1928. Although different theories about its normal position and function have been postulated, the function of the UEV remains unclear. In the present investigation we studied 118 temporal bones from 70 children to determine whether there were differences in the position of the valve and by inference, its function between children and adults. Premortem ages ranged from newborn to 10 years (mean age, 11.6 months). All temporal bones were fixed in 10% formalin, decalcified and processed by the celloidin technique. Specimens were sectioned in a horizontal plane at a thickness of 20 m. Every tenth section was stained with hematoxylin-eosin and studied by light microscopy. The position of the UEV was then classified as closed or open. Valves damaged by preparation or having an uncertain position were classified as artifact. The chi-square test was used to determine a correlation between the position of the valve and the status of the rest of the endolymphatic system and whether or not endolymphatic hydrops was present in the cochlear and vestibular systems. The UEV was closed in 39 temporal bones (33.1%) and open in 13 (11.0%). Artifacts were found in 66 bones (55.9%). In the group of patients with a collapsed ductus reuniens the UEV was closed in 38% of the specimens, suggesting that the UEV prevented loss of endolymph from the pars superior, but these findings were not statistically significant.Adapted from a presentation at the Third International Symposium on Meniere's Disease in Rome, Italy, 20–23 October 1993     

Microwave decalcification of human temporal bones

OBJECTIVES/HYPOTHESIS: Morphological and immunohistochemical studies of human temporal bones are challenging as a result of difficulties in obtaining reliably fixed specimens and the lengthy time required for decalcification, typically 4 to 7 months. A novel method of processing human temporal bones using a microwave oven to accelerate decalcification is described. This procedure provides a rapid means of decalcifying temporal bones with good preservation of tissue morphology and antigenicity. METHODS: Human temporal bone specimens obtained at autopsy (n = 12, from specimens aged 43-91 y) were fixed within 6.5 hours of death by transtympanic perilymphatic perfusion of the inner ear. Decalcification was carried out using ethylenediaminetetra-acetic acid (EDTA) in a microwave oven and required only 3 to 6 weeks. Specimens were then dehydrated, embedded in paraffin, sectioned, and mounted on slides for morphological and immunohistochemical evaluation. RESULTS: Microscopic examination revealed no obvious artifacts attributable to the microwave decalcification process. The quality of morphological preservation was largely dependent on the postmortem fixation interval and adequacy of perilymphatic perfusion. Immunohistochemical analysis demonstrated strong positive staining for the enzyme Na,K-ATPase, an integral membrane protein. CONCLUSIONS: This study demonstrates that microwave decalcification provides an efficient and reliable means of processing human temporal bones for histological and histochemical examination. Decalcification time is significantly reduced with no apparent adverse effects on structural preservation or antigenicity.     

A case of isolated ossifying fibroma of the mastoid cavity of the temporal bones

OBJECTIVES: To describe an isolated ossifying fibroma of the mastoid cavity that did not invade the inner ear and middle ear cavity. STUDY DESIGN: Case report. SETTING: Department of Otolaryngology, College of Medicine, Pusan National University, a tertiary care center in Busan, South Korea. PATIENTS AND INTERVENTION: A 34-year-old woman had an episode of acute right ear otalgia. A computed tomography scan and magnetic resonance imaging scan showed a well-circumscribed, lobulated, 3 x 3 x 3-cm sized tumor mass that was localized to the temporal bone with bony erosion including tegmen mastoid and partial bony destruction and no invasion of the middle and inner ear. A large tumor mass was removed through a simple mastoidectomy. The permanent pathological report confirmed the diagnosis of ossifying fibroma. The patient returned with complaints of recurring right otalgia, 3 years postsurgery. The previous mastoidectomy cavity was filled with a red sandpaperlike lesion; a 3 x 2-cm sized bony defect was also found,and the dura was exposed after removing the eroded tegmen mastoid. Permanent pathological diagnosis was again an ossifying fibroma,and there were no postoperative complications. CONCLUSION: To prevent clinically evident recurrences and potentially life-threatening complications, early complete resection is advised in aggressive and recurring ossifying fibroma involving the temporal bone. Close long-term postoperative follow-up with physical examinations and temporal bone computed tomography will offer the greatest chance of early detection of recurrence.     

Immunohistochemistry and microwave decalcification of human temporal bones

Processing of human temporal bones is a long, expensive process and the resulting celloidin sections are difficult to use for immunohistochemistry. We tested the ability of immunohistochemical assays to work in human temporal bones that were decalcified using a microwave oven. Tissue was trimmed to an approximate cube (1.5-2 cm/side) containing only the cochlea and immersed in fresh EDTA with paraformaldehyde every 6 h. This sized block required 190-400 h to decalcify. The decalcified tissue was embedded in paraffin and sectioned. Sections were immunoassayed with anti-cytochrome c oxidase, anti-neurofilament or anti-peripherin. All three antibodies labeled the appropriate structures. This procedure may stimulate advancement in the understanding of human inner ear pathology.     

Giant-cell tumor of the sphenoid and temporal bones

Giant-cell tumor of bone rarely occurs in the skull. There have been only 14 previously reported benign tumors involving the sphenoid and only 11 found in the temporal bone. While considered benign tumors, they are very aggressive and have a tendency to local recurrence and late malignant change with metastasis. These tumors are predominant in females and occur in the second and third decade of life. Treatment is usually with curettage and/or radiation. It is such a rare tumor that no one individual or group has had extensive clinical experience with the lesion. The purpose of this paper is to present the case of a 29-year-old physician's wife who developed frontal headache and diplopia in January of 1966. Skull films revealed a lytic lesion in the left petrous pyramid. After two incomplete removals and a full course of radiation, the tumor progressed to involve the sphenoid, clivus and a portion of the right petrous apex. A middle fossa approach, as described by House, was used to obtain a total removal of the tumor. Four and one half years post surgery, she is free of symptoms clinically and radiographically. In view of the fact that these tumors usually recur within two years this probably represents a cure.     

颞骨病理学研究的新技术应用

目的介绍用于颞骨病理学研究的分子生物学新技术.方法所有颞骨火棉胶切片均来自解放军总医院颞骨库,基于颞骨火棉胶切片的DNA提取、PCR扩增、原位杂交、原位PCR和免疫蛋白染色技术被用来研究老年性耳聋的分子病理机制.结果除了原位PCR技术,基于颞骨火棉胶切片的DNA提取、PCR扩增、原位杂交和免疫蛋白染色技术均取得了可接受的、有用的结果来帮助解释老年性耳聋的机制.结论存档的颞骨标本是非常珍贵的资源,加以利用可以揭示各型耳聋的分子病理机制.     

Hyperpneumatization of the temporal,occipital and parietal bones

Hyperpneumatization of the temporal bone with extension into the occipital bone and even the parietal bones is a rare condition. According to a review of the literature, it mostly appears unilaterally in men and on the right side. Often it is discovered when complications like pneumatocele or pneumocephalus appear. The authors review and analyze all reported cases of hyperpneumatization, its symptoms, complications and treatment. We present a patient with extensive pneumatization found in the mastoid process, temporal bone, occipital bone and both parietal bones, who was discovered accidentally. The cause of the extension of pneumatization into the occipital and parietal bone is probably incomplete closure of the occipitomastoid synchondrosis and lambdoid and sagital sutures, which usually close in early adulthood and later, even in the 30s. Asymptomatic patients should be aware of possible complications, and in case of complications, operative therapy is often indicated.     

Paget's disease and the temporal bone--a clinical and histopathological review of six temporal bones

Paget's disease of bone occurs more commonly in the elderly and has been reported to involve the temporal bone in 30% of those afflicted. The clinical and histopathological features of six temporal bones from three patients with this disease are reported and the relevant literature reviewed. The effect of Paget's disease on the middle ear structures was more variable than its extension into the otic capsule. Pagetic involvement of the otic capsule was observed in five temporal bones. One patient had bilateral asymptomatic neurofibromas in the eighth cranial nerve. the potential mechanisms responsible for the conductive deafness, the sensorineural deafness and vestibular dysfunction associated with Paget's disease are discussed.     

Histopathology of the temporal bones of deaf dogs

Histopathological studies were done in 22 deaf dogs consisting of 10 Dalmatians, 5 English setters, 2 Great Danes, 2 foxhounds, 1 shepherd, 1 bulldog and 1 Australian sheep dog. Hypoplasia or aplasia of the sensory cells of the organ of Corti, stria vascularis and macula sacculi (pars inferior) was noted in all deaf dogs examined, indicating the pathology of inner ear malformation in these dogs to be of Scheibe's type. A solidified and calcified tectorial membrane was noted in 19 out of the 22 deaf dogs. A calcified sclerosis of the tectorial membrane is thought to be a characteristic finding of genetically inherited anomaly of the inner ear in deaf dogs. Distortion of the tectorial membrane, absence of the sensory cells in the organ of Corti, agenesis of the stria vascularis and abnormalities of the saccule described Scheibe's dysgenesis of the pars inferior as the pathological correlate for deafness in these dogs as assessed functionally.     

Quantitative analysis of mRNA in human temporal bones

Conclusion. Well-preserved mRNA could be extracted from frozen human inner ears. Therefore, this study demonstrates that analysis of mRNA could be performed to study the molecular mechanisms of inner ear disorders using human specimens. Objectives. Analysis of RNA as well DNA is requisite to study the molecular mechanisms of inner ear disorders. Methods of isolating RNA from experimental animals have been established, while isolation of RNA from human inner ears is much more challenging. In the present study, we demonstrate a method by which messenger RNA (mRNA) was extracted from human inner ears and quantitatively analyzed. Materials and methods. COCH mRNA as well as GAPDH mRNA was extracted from membranous labyrinths dissected from three formalin-fixed and three frozen human temporal bones, removed at autopsy. The length of COCH mRNA and quantity of GAPDH mRNA was compared between the two groups by quantitative RT-PCR. Results: COCH mRNA could be amplified as much as 976 bp in all three frozen specimens. By contrast, it was amplified to 249 bp in two of the three formalin-fixed specimens, with no amplification observed in the remaining. The quantity of amplifiable GAPDH mRNA in the formalin specimens was only 1% of that of the frozen specimens.     

Quantitative analysis of mRNA in human temporal bones

CONCLUSION: Well-preserved mRNA could be extracted from frozen human inner ears. Therefore, this study demonstrates that analysis of mRNA could be performed to study the molecular mechanisms of inner ear disorders using human specimens. OBJECTIVES: Analysis of RNA as well DNA is requisite to study the molecular mechanisms of inner ear disorders. Methods of isolating RNA from experimental animals have been established, while isolation of RNA from human inner ears is much more challenging. In the present study, we demonstrate a method by which messenger RNA (mRNA) was extracted from human inner ears and quantitatively analyzed. MATERIALS AND METHODS: COCH mRNA as well as GAPDH mRNA was extracted from membranous labyrinths dissected from three formalin-fixed and three frozen human temporal bones, removed at autopsy. The length of COCH mRNA and quantity of GAPDH mRNA was compared between the two groups by quantitative RT-PCR. RESULTS: COCH mRNA could be amplified as much as 976 bp in all three frozen specimens. By contrast, it was amplified to 249 bp in two of the three formalin-fixed specimens, with no amplification observed in the remaining. The quantity of amplifiable GAPDH mRNA in the formalin specimens was only 1% of that of the frozen specimens.     

Study of systemic lupus erythematosus in temporal bones

Despite some reports of sensorineural hearing loss with systemic lupus erythematosus (SLE), its pathologic correlate has remained unidentified due to the scarcity of human temporal bone studies. We here present findings in 14 temporal bones from 7 patients with SLE, examined histologically and immunohistochemically for pathologic conditions in the cochlea that might relate to their otologic histories. Blue-staining concretions were seen in the stria vascularis of 6 ears. Most of the cases showed a loss of spiral ganglion cells, with various degrees of hair cell loss and atrophy of the stria vascularis. One ear demonstrated formation of fibrous tissue and bone throughout the cochlea, with complete loss of the membranous labyrinth. Cochlear hydrops was found in only 1 ear. These findings in temporal bones from patients with SLE are discussed in relation to autoimmune disease of the inner ear.     

Acoustical characteristics of surgically altered human temporal bones

The resonance qualities of the external auditory canal can increase the sound pressure level (SPL) at the tympanic membrane by as much as 20 dB between 2 and 4 kHz. Surgery on the canal, particularly in the form of a modified radical mastoidectomy, might be expected to affect this with resultant implications for speech discrimination. The creation of a modified radical mastoidectomy in 6 temporal bones altered the SPL at the tympanic membrane by +10 dB at 2 kHz, +14 dB at 2.5 kHz, -2 dB at 3 kHz, -12 dB at 3.5 kHz, -20 dB at 4 kHz, -16 dB at 5 kHz and -8 dB at 6 kHz. When this transfer function was applied to 2 subjects, speech discrimination in noise was reduced by 6%. Whether this is of any magnitude compared with the effect of the disease requires prospective studies in individuals undergoing a modified radical mastoidectomy.