The organ of Corti was studied in cats using celloidin thick serial sectioning method. The fixed temporal bones were decalcified and embedded in celloidin, then thick serial sections (100-150 μm) were cut parallel to the basilar membrane. After removing celloidin, the sections were freeze-dried in t-butyl alcohol, coated with gold and observed under a scanning electron microscope. The base and the ceiling of the Corti's tunnel and the Nuel's space, the nerve fibers and the nerve endings were constantly and easily observed. Though some outer hair cells had been deformed, the nerve fibers were well preserved for analysis.

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The nerve fibers running inside the organ of Corti was studied in cats by scanning electron microscopy, with thick serial sections method.
The tunnel spiral bundles took variable courses on the floor of the Corti's tunnel apart from the so-far reported site, medial corner of the tunnel base against the stalks of the inner pillar cells.
In the hardly-patent tunnel of Corti and Nuel's space in kitten, tunnel radial fibers ran on the floor of tunnel, slighly above the tunnel basilar fibers.
The nerve endings were not observed on the outer hair cells in 93g kitten. Fine thread-like fibers were found around the hair cell instead.

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Microtubules in the guinea pig vestibular epithelia were examined with TEM. Sensory cells contained solitary microtubules consisting of 13 protofilaments. Microtubules occurred numerously in type I hair cells, meanwhile only sparsely in type II cells. Supporting cells were characterized by some cytoskeletal bundles, which were composed of 2 to 30 microtubules. Microtubules here were also composed of 13 subunits. They were associated with actin filaments via a few number of filamentous structures.

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We examined the ultrastructure of the cochlear aqueduct using transmission and scanning electron microscope. The inner space of the cochlear aqueduct was occupied with a loose reticular connective tissue, composed of fibroblasts and collagen fibers. At the opening of cochlear aqueduct adjaceut to the subarachnoidal space, dura mater and arachnoidal tissues were lining on the bony wall of the cochlear aqueduct. At the opposite end, loose reticular connective tissues were undercoated one forth of the round window membrane, and opened into the perilymphatic space. No epithelial barrier was existed at the opening adjacent to perilymphatic space.

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We studied the vestibular pathology of the strain of the mutant C3H/He mice. Homozygotes of the animal showed head-tossing and deafness. The animals were used at ages of 10 days-18 months. At the age of 21 days, hair cell loss appears in the saccular maculae. At the age of 90 days, almost all hair cells are missing in the saccular maculae. Utricular maculae remain normal until the age of 12 months. Cristae appear preserved until the age of 18 months.

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Mouse endolymphatic epithelial cells, a layer of flat epithelial cells, were distributed on the endolymphatic surface of the mouse endolymphatic duct. The loose connective tissue was noted and irregularly protruded toward the basement membrane of the epithelial cells. It was occasionally found that both epithelial cells and the loose connective tissue protruded markedly toward the endolymphatic spaces. Consequently narrowing of endolymphatic lumen was noted in several places. There was a blood vessel, which was relatively large 40μ in diameter, running alongside the endolymphatic duct. Considering close, special arrangement of this blood vessel and endolymphatic duct, we suggested that this blood vessel played a role of fluid metabolism of the endolymphatic duct.

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The normal ultrastructure of the murine endolymphatic sac was studied by transmission electron microscopy. The epithelial cells in the intermediate portion of the sac were classified into two types. One was characterized by many mitochondria, microvilli, coated pits, vesicles, vacuoles, multivesicular bodies and lysosomes. The other was charactarized by a few of them. Extremely widened lateral intercellular spaces and apparent dark cells were not observed.

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The superior vestibular nerves and vestibular ganglion cells were observed electron microscopically in the acoustic tumor removed surgically from 6 patients. Histological changes of vestibular nerves and ganglion cells were compaired wirh caloric responses of patients. In most cases, the degrees of degeneration of myelinated nerve fibers were proportional to the reduced responses of vestibular function. The alteration of vestibular ganglion cells was unremarkable in comparison with vestibular nerves. In some cases, the number of lipofuscin granules, vacuolar organelles and amorphous materials markedly increased in the ganglion cells.

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A case of glomus tympanicum tumor was examined by light and electron microscopy. Light microscopically, the tumor was composed of anastomosing cords and nests of epithelioid cells, and highly vascular with thin-walled vessels or sinusoids. Electron microscopically, the tomor cells were classified into two types, light and dark cells according to the difference in the cytoplasmic density. The dark cells were predominant in number, and their cytoplasm was packed with numerous mitochondria which resemble those of oncocytes. The tumor cells contained spherical dense core granules. These granules were found predominantly in the dark cells. It is now suggested that these granules can produce biogenic amines or polypeptides.

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The purpose of this studies is to describe the three-dimensional image of external auditory canal (EAC) using computer-graphics methodes. For reconstracting the three-dimensional structure of EAC, a set of CT slice of temporal bone was prepared and image processing system was cosmosonell SA (Nicon). By this technique, three-dimensional image of EAC was clearly seen and EAC could be divided to several types, for examples, streight type and curved type etc, depending on their three dimensional image. Furthermore, three-dimensional relationships between EAC and the head of mandibular joint were described.

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The purpose of this study is to describe the three dimensional image of human internal auditory canal (IAC) using computer-graphics methods. For reconstructing the three-dimensional structures of IAC, a set of CT slices of temporal bone was prepared, and image processing system was cosmosone II SA Nicon. By this technique, the three dimensional image of IAC is clearly seen. The shapes of the canal can be classified into three types, cylindrical type (medial portion is almost same as lateral portion), Cone type (lateral end is greater than medial end) and oval type (middle portion was greater than either end of canal).

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Images of three-dimensional graphic reconstruction (3-D GR) on five human bony labyrinths using the computer-aided serial section reconstruction system (SERSERS) were compared with that of two-dimensional graphic reconstruction (2-D GR) developed by Egami and Sando. The results obtained were as follows. 1) In 2-D GR, positions of the vestibular aqueduct (VA) and the paravestibular canaliculus (PVC) lay more backwards to the posterior semicircular canal, the angle of VA was wider and VA was more elongated backwards, than in 3-D GR. 2) Two PVCs were seen in only one case.

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Operator is usually forced to remove inflammatory tissues near or around the stapes in middle ear surgery. We often experienced post operative sensorineural hearing loss in spite of much care of operative procedure. To study influences of inner ear due to eperative procedure, experimental different three conditions were made using guinea pigs. These are pushing stapes into cochlea directly with a needle, making a small perforation to the scala tympani of the cochlea by small burr and stapes mobilization. The first two conditions occur perilymph fistula and last one occurs the pressure change in perilymph indirectly. The conditioned guinea pigs were sacrificed just after the operation, 7 days later and 1 month later, and then cochlea were removed. Under light and scanning microscope, organ of corti was examined. Damage were observed mainly in outer hair cells of 2nd or 3rd turn.

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Cochlear changes produced by chronic perilymphatic fistula were studied by inserting a 0.47mm dia. plastic cannula into the scala tympani of the basal turn of the cochlea of guinea pigs. About a month later, changes in cochlear blood flow and hair cell morphology were studied using the microsphere surface preparation technique. When the tube was patent and confined to the scala tympani, no cochlear histopathology was evident. In some animals, hair cell damage and reduction in cochlear blood flow was present, perhaps due to direct tubal injury to the cochlear duct or to an unknown factor induced by the chronic fistula. Therefore, a chronic perilymphatic fistula limited to scala tympani causes no cochlear damage.

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Lipoteichoic acid from Staphylococcus aureus was used in this experiment in order to see the possibility of cochlear damage due to endotoxin-like substance in the middle ear fluid. The substance was either put on the surface of the round window membrane or injected into the scala tympani of guinea pigs, and the temporal bones were obtained and processed for evaluation under light microscope. In the former group, no definite abnormality of the cochlea was observed. However, in the latter group in which the substance was injected into the scala tympani, severe inner ear damage was observed in some of the animals. The results may indicate the possibility that the cochlear damage might occur by endotoxin-like substance which has penetrated the round window membrane into the inner ear.

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Complements are known to relate to many inflammatory reactions. C4a C3a and C5a, known as anaphylatoxins, are known to cause strong inflammatory reactions. In this study, the influence of anaphylatoxins to the cochlea from the tympanic cavity was observed. Fifteen male Hartley guinea pigs, weighing about 350grs, all susceptible to preyer's reflex, were used in this study. Anaphylatoxins were made from guinea pig serum treated with zymosan, and were inoculated into the tympanic cavity of guinea pigs. Pathological changes in the inner ears were observed by light microscopy. Reissner's membranes were collapsed in some animals (60%). The stria vascularis in the various cochlear turns were extremely atrophied (40%) and some cochlear nerves showed degeneration. These results suggested the influence of anaphylatoxins to the cochlea from the middle ear.

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Electron microscopic study was performed on the tympanic plexus taken from patients during ear surgery. The nerve bundles of the plexus consisted of mostly myelinated fibers and unmyelinated fibers distributing among them. Ganglion cells were found along the course of the nerve bundles. Nerve endings, containing many agranular vesicles, formed synaptic contacts with cell bodies of these ganglion cells. As these nerve endings were suggestively cholinergic, ganglion cells were autonomic. We speculate they belong to the parasympathetic system.

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The anterior attic bony plate separeting the supratubal recess and the epitympanum is seemed to act an important role in the pathogenesis of middle ear cholesteatoma. There are many reports on embryological study of the human temporal bone, however reports studied from the point of pathogenesis of cholesteatoma are few. In this report, embryological findings on middle ear spaces of human fetus were studied. The materials used were slised in seriese on the plane of OM-30 and analysed 3 dimantionally. As result, some different findings from the previous reports were found, especially on the direction of development in the tympanic spaces.

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The structures of the bony modiolus in the human cochlea were examined by scanning electron microscopy (SEM). The spiral canal for the spiral ganglion and spirally running spaces for the modiolar artery and anterior and posterior spiral veins in the modiolus showed openings or windows leading to the perilymphatic space.

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The effect in the central vestibular system of the rats by galvanic stimulation were investigated immunohistochemically using antisera against GABA. GABA-like immunoreactivity in the lateral vestibular nucleus showed more intensive on the side ipsilateral to the anodal stimulation compared with the other side. It was concluded that the galvanic stimulation causes an imbalance of the inhibitory effect to the lateral vestibulo-spinal tract.

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The cholinergic nerve system was examined by Karnovsky's method in the cynomolgus (macaque) monkey. Acetylcholinesterase (AchE) was demonstrated in the efferent fibers. Most of the efferent fibers headed to the organ of corti from the intraganglionic spiral bundle, however, some unmyelinated efferent fibers changed direction to make synaptic contacts with the perikarya and central and peripheral process of type II ganglion cells. Besides the efferent fibers, type II neurons also demonstrated AchE activity on the cell surface and their neurites, suggesting that the AchE-positive fibers in the simian nerve trunk, previously believed to be of efferent origin, are the central processes of type II neurons. These observations indicated that the olivocochlear efferent system in the cochleas of monkeys differ from those of smaller animals.

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Several neuropeptides were observed in the efferent nerve to the outer hair cell. It is very interested whether these peptides control the outer hair cell or not. The effects of calcitonin gene-related peptide (CGRP) and enkephalin on the cytoplasmic free Ca²⁺ concentration of single outer hair cell ([Ca²⁺] i) were monitored by digital imaging microscopy using fura-2. An increase of [Ca²⁺] i was seen in the solution with enkephalin but no response of [Ca²⁺] i was seen in the solution with CGRP.

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Gamma aminobutyric acid (GABA) -positive terminals were found around cell bodies in the acoustic nerve nucleus (ANN) of rats, mongolian gerbils and mice. In rats there were numerous strongly-stained GABA-positive nerve terminals, but in mongolian gerbils and mice scarce and stained more weakly. Nerve terminals originating in the spiral ganglion have been reported to synapse with cell bodies in ANN, but the spiral ganglion cells containing GABA have never been reported. It was considered that two types of terminals, GABA-positive and GABA-negative exist around the cell bodies of ANN.

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Immunocytochemical double staining analysis revealed that some of the calcitonin gene-related peptide-containing neurons in the lateral superior olivary nucleus which project to the cochlea contained enkephalin in the guinea pig.

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KOS strain of HSV type I was instilled in the right middle ear cavity of normal rats. After inoculation, the vestibular ganglions were resected and submitted to histopathological and immunohistochemical investigations on the day in the experimental time schedule. The specimen of the 3, 4, 5th day after inoculation showed inflammatory changes in the vestibular ganglion on the side of inoculation. By immunofluorecent antibody staining, HSV antigens were proved in both sides in the specimen of the 1st and 5th day after inoculation, but in the 8th day, HSV antigens were not detected.

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Dengue virus was injected into the facial canal of the guinea pig from the stylomastoid foramen. It had been proved that the injected materials reach the inner ear via the cochlear and vestibular nerves.
Animals were sacrificed 4 weeks after the injection. Temporal bones were examined light microscopically. Prominent findings were;
1) Edematous swelling of the mucoperiosteum of the middle ear.
2) Marked swelling and slight degeneration of the facial nerve.
3) Partial degeneration of cochlear neurons in tne osseous spiral lamina.

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In 6 adult hamsters, acute viral labyrinthitis was induced by inoculation of measles virus into perilymphatic space of the 6 cochleae. 4 to 7 days after inoculation, the cochleae were removed and examined with light and immuno-fluorescent microscope. 5 cochleae showed erythrocyte and mononuclear cell infiltration which was profound in the endolymphatic space and less profound in the perilymphatic space. The organ of Corti showed degeneration, and the tectorial membrane separated from the spiral limbus, rolled up and adhered to the stria vascularis in the middle turns. Immunofluorescent microscopy demonstrated presence of viral antigens in the rolled up tectorial membrane and mononuclear cells.

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Herpes simplex virus 1 strain KOS was inoculated to the right auricle of 36 balb/c mice. The data of four mice were excluded because of death. Of the remaining 32 mice, 28 (87.5%) developed ipsilateral facial palarysis between 6 and 9 days after the inoculation. The palarysis lasted for 3 to 7 days in 8 mice which did not recur during follow up of more than 6 months. Four died after occurrence of the facial nerve. Sixteen mice were killed for histological study of the facial nerve. Inflammatory changes, such as round cell infiltration and degeneration of the geniculate ganglion cells, were observed all animals. Herpes simplex virus antigens were indentified in the geniculate ganglion cells, satellite cells and nerve fibers.

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In the secondary endolymphatic sac (e. sac) immune responses against KLH, the characterization of Na⁺ and K⁺levels in perilymph over 6 days was investigated in Hartley guinea pigs. No significant difference of Na⁺and K⁺level was seen between the KLH challenged ears (right) and the KLH unchallenged ears (left). At day 2-3, a marked cellular infiltration within the e. sac was seen. Endolymphatic hydrops started from 1st day and rapidly increased to maximum on 2nd day. These results stiggested that the inner ear dysfunction might be mainly caused by direct damage through some agents of inflammatory mediator and acute formation of the endolymphatic hydrops rather than change of Na⁺and K⁺level in perilymph.

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To investigate the distribution of IgG and C3 complement in the inner ear over a 4week period as a result of a secondary endolymphatic sac (ES) immune response against keyhole lympet hemocyanin (KLH), immunohistochemical methods were used. Guinea pigs were employed and antibodies against KLH, guinea pig IgG and C3 complement were used. At days 2-3, moderate endolymphatic hydrops were observed within the inner ear with a massive cell infiltration within the ES and then gradually decreased in the degree (Fig. 1). Diffuse IgG and C3 stainings were localized within the ES, the epithelial and subepithelial region of the vestibule, as well as the spiral ligament and the hair cells in the almost same manner after antigen challenge. IgG bearing cells were detected only within the perisaccular region.

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Spontaneous nystagmus was examined each eight hours after secondary endolymphatic sac immune response. Spontaneous nystagmus was seen in 13 of 19 animals. Direction of nystagmus was contralateral unchallenged side (left). Nystagmus appeared within 3 days. Duration of nystagmus was from 1 day to 4 days. Spontaneous nystagmus was found in all animals of which caloric responses resulted in afunction.

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We investigated relationships between inner ear pressure and cochlear blood flow measuring carotid blood pressure in guinea pigs. A glass capillary tube was inserted into the perilymphatic space and fixed to the bone with dental cement to prevent leakage. When hydrostatic pressure was applied to perilymph through the capillary, endolypmh pressure and perilymph pressure varied coincidentally. Cochlear blood flow measured by a laser Doppler flowmeter decreased upon the elevation of the inner ear pressure. In hypotensive animals, the inner ear pressure required for lowering the cochlear blood flow was low. We consider that cochlear perfusion pressure can be calculated as the difference between the mean arterial blood pressure and the inner ear pressure.

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Relationships between arterial O₂, saturations and cochlear microcirculation of guinea pigs were observed using pulse oxymetry, blood gas analyser, laser Doppler flowmeter and PO₂, monitor. Since the present study using 18 guinea pigs indicated a close correlation in arterial O₂ saturations between data by blood gas analysis and those by pulse oxymetry, recording of arterial O₂ saturation using a pulse oxymetry is considered to be feasible for monitoring the condition of respiration during the animal experiment concerning cochlear microcirculation. In asphyxia loading, the response of perilymphatic O₂ tension was found to be slower and less in as degree compared with that of arterial O₂ saturation.

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We experimentally produced hydrops in guinea pigs by silver nitrate injection method. Some of them so treated were then exposed to sound for 2 hrs (1KHz, 120, dB). And there were circularly disturbance in their cochleas, especially stria vascularis. In the cochleas of these guinea pigs after glycerol administration, there were no findings of local circulatory disturbance. We suggested glycerol effect improved local circulation in the cochlea.

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Experiments were performed in an attempt to compare the vulnerability of avian inner ear against noises to those of mammals. Parakeets were exposed to white noise of 110 dB SPL for 5 hours. After confirmation of a rise in threshold of the evoked response audiometry, their cochleae were fixed and morphologically examined. It has been reported that, in guinea pigs, noise exposure resulted in both NIPTS and changes of hair cells revealed by scanning electron microscope. However, this study suggested that, in parakeets, the same exposure caused NITTS and no major changes of hair cells could be observed by light and transmission electron microscope.

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The effect of head position on the second phase of caloric nystagmus was investigated in three rhesus monkeys. The monkey was seated in a gimbal chair with the head held in a position 15° down. Eye movements were recorded three dimensionally, using a three-magnetic coil system. The 20°C water was irrigated into the external canal and the first phase of caloric nystagmus was recorded either in the supine or in the prone position. During the second phase of caloric nystagmus, the monkey was positioned on the side either 90° right ear up or down, or upright. In the supine or prone position, the torsional nystagmus component was predominant. In the upright position, the horizontal component was the most intensive. In the side positions, the vertical component was predominant. We put forward the hypothesis that this response pattern mainly reflects otolithic function.

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A computerized recording-analysis system of auditory evoked responses for laboratory animals is developed. The stimulation system is controlled using a GPIB board in a slot of the personal computer PC-9801 (NEC), and the signals generated by the animal are amplified and then digitalized by an A/D converter also mouted in the computer. The following parameters are controlled on the keyboard: averaging count; sampling time; timing to start rejecting data; wave form, frequency, phase and attenuation of stimulus sound. Auditory evoked responses of experimental perilymphatic fistula guinea pigs are studied with this system and over one-third of the animals showed residual hearing between 10 and 14kHz.

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We observed the relationship between the internal carotid artery and the eustachian tube using forty human temporal bones. The distance between them had the tendency to be longer as the observed sectional plan was separated further from the cochleariform process. It was influenced by the degree of pneumatization between them and the position of the tubal cartilage, not by the correlation between the middle ear and the internal carotid artery.

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Recently the cause and effect relationship between medial high jugular bulb and inner ear disease, such as sensorineural hearing disturbance or Meniere's disease, has been reported in some articles. It was supposed that inner ear disease was caused by stenosis of internal auditory canal or endolymphatic duct obstruction. We studied temporal bone findings of medial high jugular bulb in 293 temporal bones. The result was as follows:
1) Medial high jugular bulb seems to have no effect on internal auditory canal.
2) There are some possibilities that medial high jugular bulb has an effect on development of periaqueductal pneumatization and of endolymphatic duct and endolymphatic sac.

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The aim of this paper is to elucidate the anatomic variation of the jugular fossa (JF) on the basis of examination 65 human temporal bones. Observations were made on temporal bones sectioned along a plane including the cochlea, the JF, and long axis of the internal canal. The result reveals that 26 out of 65 ears are type I, 29 are type II, and 10 are type III. In 60% of ears the upper margin of the JF higher than the floor of tympanic cavity, and in 89% of ears the former is situated medially in the latter. In conclusion, protrusion of the jugular bulb into the tympanic cavity is not caused by the abnormal higher JF, but by its lateral displacement.

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Funicular structure of the extratemporal facial nerve in man was investigated by serial cross section of the specimen taken from a patient of parotid tumor. The facial nerve was composed of a few funiculi separated by thin perineural sheaths at just distal of the stylomastoid foramen. The bundles of the nerve increased in number and the perineural sheaths became thicker at the periphery of the distal portion. The intermingling and funicular redistribution of fibers by repeated changes in the funicular pattern were observed in the lower main branch. These findings suggested that there were no spatial orientation in the branches at this level of the facial nerve.

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The histopathologic findings of five patients with trisomy 18 syndrome are discribed. Three patients have low-set ears, and two have auricular malformations and atresia of the external auditory canals. The chief findings are as follows; aberrant course of the facial nerve with an obtuse angulation at the first genu (2 bones), malformed stapes (3 bones), shortened cochlea (3 bones), flattened cochlea with underdeveloped modiolus (6 bones), decreased spiral ganglion cell population (7 bones), enlarged vestibule (7 bones) and semicircular canal (8 bones). There can be seem bony atresia of the round window, which is unreported previously.

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When we treat patients of otitis media, we first examine the tympanic membrane to know the condition of inflammation of tympanic cavity. We examined the pathogenesis of the tympanic cavity of each case of acute inflammation and chronic inflammation of pars tensa, and cases where there were no findings of inflammation in the pars tensa. In most cases of acute inflammation of pars tensa, inflammation of tympanic cavity was acute; in chronic inflammation of pars tensa, chronic. It was interesting that, even in cases of normal pars tensa, inflammation was frequently found in tympanic cavity. Therefore, it is important to pay attention to the possibility of inflammation in tympanic cavity, even if the tympanic membrane appears normal.

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Two cases of brain death are reported in which the auditory brainstem responses were recorded at cessation of cortical activity, and in which histological examination of the temporal bone and brainstem auditory pathways was performed postmortem. Brain death of 48 hours' duration in case 1 and 16 hours' duration were demonstrated. The pathological studies revealed total autolysis of the organ of Corti in two cases, marked cell loss in the dorsal cochlear nucleus, and moderate cell loss in other nuclei of the central auditory pathway. It should be considered that total autolysis of the organ of Corti may occur at least during long lasting brain death.

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We examined human temporal bone histopathology in subarachnoid hemorrhage in order to study how red cells from internal auditory meatus had an effect on the inner ear and facial nerve. It was revealed that red cells from internal auditory meatus tended to enter perilymphatic space of cochlea, utricle, saccule, and semicircular canal when subarachnoid hemorrhage was severe. In facial nerve, red cells also tended to enter peripheral region in cases of severe subarachnoid hemorrhage. Until now it was thought that red cells entered perilymphatic space of cochlea from cochlear aquaduct. But this research showed that red cells entered inner ear not only from cochlear aquaduct but also directly from internal auditory meatus.

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Serial section of 20 temporal bones taken from 10 patients with leukemia were studied histopathologically. Inspite of showing pathological findings due to leukemia in all cases, the otological symptoms such as vertigo, facial palsy, sudden deafness, and mass formation of external auditory canal were manifested in only 4 cases. Hemorrhagic changes found particularly in internal auditory meatus of 18 ears, middle ear of 12 ears, and external auditory canal of 8 ears. Leukemic infiltration was observed in internal auditoty meatus of 12 ears, middle ear of 11 ears, and external auditory canal of 6 ears. It was noted that otological symptoms of various types were caused by hemorrhage and or leukemic infiltration into the temporal bone and leukemic pathological change could happen in any site of the temporal bone.

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The histopathology of the formation of cholesterol granuloma as seen on horizontal sections of 8 human temporal bones in 7 subjects with chronic otitis media have been divided into 3 stages based on its pathophysiology. The lst stage is cholesterol crystal formation, found in 7 (87.5%) temporal bones; the 2nd stage is the foreign body giant cell reaction, found in 4 (50%) temporal bones and; the last stage is the fibrous tissue formation also found in 4 (50%) temporal bones. All three stages were seen together in one temporal bone in 3 cases. The eustachian tube was found to be lined by thickened mucosa and patency blocked by effusion, inflammatory cells and debris in 6 (75%) temporal bones. Seven mastoid bones were found to be diploetic and only one was sclerotic. Cholesteatoma was seen adjacent to cholesterol granuloma in the hypotympanum in one temporal bone, however, no evident connection between the two was found.

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The temporal bone was examined in a 35-year-old female with Wegener's granuromatosis. Her disease localized in the nasal cavities and the orbita, but did not exist in the lung and the kidney. The pure tone audiometry showed the moderate combined deafness of both ears. Right temporal bone findings: The surroundings of the auditory ossicles, epitympanum and eustachian tube were filled with fibrous tissue. The cochlea showed slightly flattend organ of Corti and slightly collapsed Reissner's membrane. The internal auditory canal was infiltrated with leukocytes. The VIIIth nerve was not degenerated. Left temporal bone findings: The hypertrophic submucous tissues and fibrous tissue were seen in the middle ear.

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Temporal bone pathology of five cases who died of invasion primary cancer of the ear were studied. In case 1, carcinoma originated from the external ear and treatment consisted of mastoidectomy and postoperative irradiation. A histopathological study revealed extensive invasion of carcinoma in the mastoid cells and posterior fossa destroying the pyramis, however, no invasion into the labyrinth was found. In case 2 and 3, carcinoma originated from the middle ear and subtotal resection of the temporal were done after irradiation. Case 2 who died of meningitis demonstrated no existence of carcinoma on histopathological study. Case 3 who died of recurrence of carcinoma in the postoperative area of the temporal bone, showed persistence of carcinoma in the eustachian tube. In case 4 and 5, carcinoma originated also from the middle ears. Irradiation therapy was given in case 4 and mastoidectomy was done in case 5, after preoperative irradiation. Histopathological studies revealed extensive invasion in both temporal bones. This study suggests that inner ear is resistent to invasion of carcinoma and irradiation, but the mastoid bone is susceptible to invasion of the carcinoma and is apt to become a route for intracranial invasion.

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Two cases of metastatic involvement of the temporal bone by malignant tumors are presented. Case I: Metastatic hepatic cell carcinoma. At age 65 the patient noted a progressive left facial palsy, followed by otalgia and hearing loss. At examination, there was a large mass in the left external ear canal. She died 5 months later of diffuse carcinomatosis. Histologic studies show extensive osteolytic metastic lesions involving both the tympanic and mastoid parts of the left temporal bone. The facial nerve has been completely destroyed by neoplastic tissue. Case II: Metastatic bronchogenic carcinoma. At age 68 the patient complained of an enlarging mass with pain at the left mastoid area. He died 6 months later of bronchopneumonia. Examination of the left temporal bone reveals undifferentiated squamous cell carcinoma tissue invading the tympanic cavity and mastoid air cell system.

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