Anatomy of the temporal bone

High resolution computed tomography has proved to be invaluable in the evaluation of the temporal bone, and demonstrates its bony anatomy in exquisite detail. Furthermore, the role of magnetic resonance imaging, especially with improving high resolution techniques, has continued to expand in the past decade. A thorough understanding of normal temporal bone anatomy is a requisite for accurate radiologic evaluation. The ensuing discussion is an attempt to summarize the normal temporal bone anatomy with emphasis on clinically relevant structures, temporal bone pneumatization, and common anatomic variants.     

Giant cell tumor and temporal bone

Receptors for regulatory peptides such as somatostatin or vasoactive intestinal polypeptide are expressed by a number of human neoplasms and can be visualized in vivo with peptide receptor scintigraphy. Recently, the CCK-B receptor, which binds both gastrin and cholecystokinin with high affinity, was shown using in vitro methods to be overexpressed in a number of human tumor tissues, including medullary thyroid carcinomas, small cell lung cancers, astrocytomas, gastrointestinal tumors, and stromal ovarian cancers. In the present study, we have designed novel, unsulfated CCK octapeptide analogs linked to the metal chelating DTPA and DOTA, and have tested them for their binding affinity to CCK-B receptor-positive tissue from human tumors: The most potent compounds assayed were DTPA-[Nle28, 31]-CCK(26-33) (MP2286) and DTPA-[d-Asp26,Nle28,31]-CCK(26-33) (MP2288) with an IC50 of 1.5 nM. For comparison, analogs with C-terminal DTPA, such as [Nle28,31,Aphe33(p-NH-DTPA)]-CCK(26-33) and CCK-(26-33)-NH(CH2)2 NH-DTPA, had an IC50 of >100 nM. DOTA-[D-Asp26, Nle28,31]-CCK(26-33) had an IC50 of 3.9 nM. The compounds were selective for CCK-B receptors as they did not bind with high affinity to CCK-A receptors expressed in human tumors (meningiomas or gastroenteropancreatic tumors). In vivo rat biodistribution studies with indium-111 labeled MP2286 and MP2288 showed that the primary mode of clearance was renal, and the primary sites of uptake (% ID/g 24 h p.i.) were kidneys (0.270 and 0.262, respectively) and the gastrointestinal tract. The CCK-B receptor-expressing gastric mucosa showed specific in vivo accumulation of 111In-labeled MP2288 which could be blocked in the presence of excess unlabeled MP2288. 111In-labeled MP2286 and MP2288 were also found to be stable in human plasma whereas both compounds were degraded in urine (>40% after 3 h at 37 degrees C). The affinity, specificity, biodistribution, and stability of these two DTPA-CCK analogs indicate that these compounds have substantial promise for use in the in vivo visualization of CCK-B receptor-expressing tumors.     

Congenital cholesteatoma of temporal bone

Cytomegalovirus infection causing symptomatic enteritis is most usually associated with immunosuppressed transplant patients or patients positive for human immunodeficiency virus. Most reports studying this illness are small and do not clearly define the risk factors or mortality rates. METHODS: The present study retrospectively reviewed the charts of 67 patients with biopsy-proven cytomegalovirus enteritis (esophageal, gastric, small bowel, and colonic) to define and to investigate factors that influence survival. Patients were classified into four groups based on underlying medical condition: 1) patients positive for human immunodeficiency virus; 2) transplant patients receiving immunosuppressive medications; 3) immunosuppressed nontransplant patients; and 4) otherwise healthy individuals. Mortality rates based on underlying medical condition, location of intestinal cytomegalovirus infection, cytomegalovirus therapy, age, and average days to institution of treatment were defined and statistically assessed. RESULTS: Mortality was significantly greater in the normal patient group (80 percent) than in the transplant (21 percent), other immunosuppressed (44 percent), or human immunodeficiency virus-positive (75 percent) groups (P = 0.0006, Cochran-Mantel-Haenszel statistics). There was no difference in mortality based on intestinal location of disease or treatment modality (surgery, medical therapy, or both). Cohorts of patients older than 65 years had a statistically higher mortality rate vs. those younger than 65 years old (68 vs. 38 percent; P = 0.05, Cochran-Mantel-Haenszel statistics). Statistically increased mortality was also associated with increased time from hospital admission to institution of cytomegalovirus treatment, whether therapy was medication alone or medication and surgery (P < 0.05, exact Wilcoxon's test). CONCLUSIONS: 1) Lethal cytomegalovirus enteritis can arise in patient populations not typically identified as being at risk for this disorder, including normal individuals. 2) Mortality in cytomegalovirus enteritis is adversely associated with age older than 65 years and increased time to institution of therapy but is not affected by anatomic site of infection or particular form of treatment. Paradoxically, in this study, normal patients had the highest mortality, which we attribute to a low index of suspicion and relatively late institution of therapy.     

Meningiomas of the temporal bone

Meningiomas should be considered in the differential diagnosis of otologic tumors arising from the middle ear and mastoid. It is generally recognized that meningiomas may invade the temporal bone via direct extension from the intracranial space (secondary). It is not generally recognized that meningiomas can develop initially in the middle ear cleft (primary). Representative cases of primary and secondary meningiomas of the temporal bone are described and clinical aspects of diagnosis surgical management are discussed. In order to assess the pathogenesis of meningiomas of the temporal bone, histological studies were done on 200 temporal bone specimens. In certain specimens, ectopic arachnoid granulations, from which primary meningiomas may originate, were identified and described, according to location. One specimen was most unusual in that it contained ectopic glial as well as arachnoidal tissue.     

Inflammations and tumors of the temporal bone

The term 'inflammation of the middle ear' covers a couple of diseases which range from the acute otitis media to the middle ear cholesteatoma. However, a clear characterization of a certain pathology is essential for any further treatment. Therefore this article presents a short overview about the different types of infections and their clinical manifestation. The tumors of the temporal bone show a great variety in their incidence. Even if tumors like the acoustic neurinoma or the paraganglioma are comparatively common, the chondroblastoma of the temporal bone is absolutely rare. In spite of these differences the individual temporal bone neoplasias are shortly mentioned herein.     

Glomus tumor of the temporal bone

A case story describing the typical symptoms and course of a glomus tumour of the temporal bone is presented. The most frequent symptoms are pulsatile tinnitus, unilateral hearing loss, aural fullness and paresis of the vagal nerve or other lower cranial nerves. The tumour is frequently visible by otoscopy. Despite being histologically benign, the tumour is infiltrative and may affect the surrounding cranial nerves or spread into the cranial cavity. The early signs and findings are vague. Since the sequelae are fewer when the tumour is treated while it is small, an increased awareness will be of benefit to the patients.     

Desmoplastic fibroma of the temporal bone

BACKGROUND: Desmoplastic fibroma is a benign, locally aggressive, intraosseous neoplasm with a propensity for local recurrence. Desmoplastic fibroma most commonly originates within the mandible (70% of cases), and long bones with rare lesions reported in the maxillary, frontal, and parietal bones. We report two patients with desmoplastic fibroma arising within the temporal bone. STUDY DESIGN: Case report and literature review. PATIENTS: Two patients with desmoplastic fibroma with intracranial and extra cranial growth patterns are presented. Both were young females with aural fullness and decreased hearing. INTERVENTIONS: Diagnostic and therapeutic. RESULTS: Both tumors were surgically extirpated and the patients have remained disease free for 18-48 months. Neither tumor expressed estrogen or progesterone receptors. CONCLUSION: Desmoplastic fibroma is a highly invasive local destructive lesion which is best treated by nondestructive surgical intervention. Immunohistochemical analysis may demonstrate hormonal receptors, in which case Tamoxifen may reduce recurrence.     

Acute intracranial complications of temporal bone trauma

BACKGROUND: A total of 110 patients, in whom kidneys from 95 living related and 15 cadaver donor, had experienced renal transplantation between February 1985 and October 1996 in our clinic. This study was conducted to evaluate the influence of the various pre-operative factors to the graft survivals and clinical course of patients in living related renal transplantation. METHODS: In 95 recipients, 17 adult patients had long term graft survivals over 5 years including 6 recurrent or denovo nephritis without chronic allografts nephropathy. Eight failed to graft loss attributed to chronic allografts nephropathy diagnosed within 5 years. Retrospective analysis were performed to elucidate the differences of these recipients. RESULTS: Donors of long graft survival recipients were younger (49.1 +/- 12.1 v.s. 58.9 +/- 10. 2) and had a better renal function evaluated by preoperative creatinine clearance in living related donors (115.5 +/- 37.0 v.s. 79.7 +/- 22.0 1/day). Graft long survival recipients had experienced less frequencies of acute rejection within 6 months (0.53 +/- 0.62: 8 patients, 9 times) compared with chronic allografts nephropathy recipients (1.00 +/- 0.53: 7 patients, 8 times). Long graft survival recipients had better responses to the antirejection therapy. Additionally acute rejection over 6 months were experienced only in chronic allografts nephropathy recipients. Higher serum creatinine level was revealed in recipients with chronic allografts nephropathy at 1 year after transplantation (1.27 +/- 0.27 v.s. 1.88 +/- 0.42 mg/dl). CONCLUSIONS: We concluded that donor age and renal function are related to the graft long survival as background factors. Long graft survival recipients had less frequency of acute rejection and good response to the antirejection therapy. In recipients with of acute rejection and good response to the antirejection therapy. In recipients with chronic allografts nephropathy, serum cretine level had already increased gradually within 1 year.     

Infantile myofibromatosis located in the temporal bone

Infantile myofibromatosis (IM) is a proliferative disorder of infancy and early childhood characterized by the nodular or diffuse growth of lesions that are comprised of a mixture of mesenchymal elements. Intracranial involvement is reportedly rare, only eight such patients having been reported to our knowledge. We report on a 4-year-old boy with intracranial IM with a mass in his left temporal bone. A previous report on intracranial IM proposed that the underlying dura mater should be resected because of the possibility of early recurrence. At surgery in this case, the tumor was noted to be located in the bone itself and did not arise from the underlying dura. Therefore, the underlying dura mater and venous sinus were preserved. The follow-up MRI showed no sign of recurrences. It may not to be necessary to resect the dura mater in patients with intracranial IM.     

3-D morphological study of the temporal bone

OBJECTIVE: To establish the 3-D(three-dimensional) morphological study of the temporal bone by means of computer graphic techniques. METHODS: The serial sections of the temporal bone were processed by the technique of computer-aided 3-D reconstruction. The 3-D images of the multi-structures in the temporal bone were displayed on the monitor. The 3-D parameters of these structures were measured by a special software. The stereo-images of the structures in the temporal bone were obtained by stereoscopy and stereo-pairs. RESULTS: Most structures of the temporal bone were reconstructed in 37 instances for the different purpose of study. Each set of the stereo-pair corresponding to the structures in the temporal bones and many 3-D parameters were obtained. The complex spatial relationship among the reconstructed structures such as the facial nerve, endolymphatic sac, posterior tympanum and posterior ampullary nerve was revealed and the mechanic model of the ossicular chain was set up. According to these results, the surgical approach of the posterior ampullary nerve transection was designed and simulated on the graphic computer. CONCLUSION: The technique of computer-aided 3-D reconstruction provides a new tool for the study of the temporal bone. It is also helpful for the designs and simulations of the surgical approaches. The results of this study contribute to developmout of a new branch of pathology of the temporal bone and a primary 3-D morphological study of the temporal bone.     

Parapharyngeal emphysema--an unusual complication of temporal bone trauma

Medical cure of fungal prosthetic valve endocarditis (PVE) is rarely reported. We describe a patient with C. tropicalis PVE in whom surgery was believed to be contraindicated. A huge tricuspid valvular vegetation was identified by two-dimensional transthoracic echocardiography. After a total of 2 g of amphotericin B, she continued with fluconazole daily with a follow-up of fifteen months. Our patient represents the first case of long term survival of C. tropicalis PVE successfully managed without surgery.     

Effect of insulin-like growth factor-1 on zygomatic arch bone regeneration: a preliminary histological and histometric study

A number of physicians have attempted to pharmacologically manipulate the healing of bony fractures with a variety of agents such as growth hormone, thyroxine, chondroitin sulfate, and parathyroid hormone. Thus far, results from these experiments have been inconclusive. Previous research dealing with insulin-like growth factors has centered on cultures of osteoblast-like cells and has demonstrated a stimulatory effect on bone collagen synthesis, which may in fact play a critical role in the process of bone formation itself. The purpose of this investigation was to examine the effects of a genetically engineered growth factor, insulin growth factor type I, on midfacial fracture healing. In 24 adult male Sprague-Dawley rats, a standardized defect was created within the midportion of each zygomatic arch. One-half were treated with insulin growth factor type I administered with an osmotic infusion pump and the other half served as control subjects. At 2, 4, 8, and 12 weeks, animals from each group were killed and specimens of the defect obtained. Data were collected from radiographs and histological studies to compare the extent of bony repair. From this study, it appears that insulin growth factor type I could exert a potentiating effect on the repair of midfacial bone defects.     

Simultaneous leukaemic infiltrate and cholesteatoma in the same temporal bone

An otherwise healthy 37-year-old man came to the emergency room with left-sided dull chest pain of 4 weeks' duration. Physical examination, laboratory studies, and electrocardiogram were all unremarkable. A chest x-ray film revealed calcified pulmonary nodules. Computed tomography of the chest confirmed bilateral parenchymal cavitary lesions. Via limited thoracotomy, a tan nodule measuring 2.5 to 3.0 cm in diameter was excised from the left upper lobe. Histopathologic examination revealed a well circumscribed lesion and extensive lamellar hyalinization. A few foci of finely granular calcification were present within the hyalinizing areas. After surgery and short-term use of nonnarcotic analgesics, the chest pain resolved. Although pulmonary hyalinizing granuloma (PHG) is known to produce cavitating lesions, calcification at multiple sites is also consistent with this diagnosis. Clinicians should remember to include PHG in the differential diagnosis of multiple pulmonary nodules.     

Clinical and surgical application of reformatted high-resolution CT of the temporal bone

High resolution CT has played a pivotal role in temporal bone imaging since the early 1980s. Although the appearance of MR imaging technology with its superior demonstration of fluid-containing spaces of the inner ear and the posterior fossa structures, CT continues to offer distinct advantages for the evaluation of conductive hearing loss, and petrous apex lesions. With the advent of helical scanning techniques, CT is increasingly the imaging study of choice for definitive preoperative temporal bone imaging.     

Various types of suprameatal spines and depressions in the human temporal bone

Since it covers the lateral wall of the mastoid air system, the suprameatal triangle is of importance to otologic surgeons during mastoidectomy. Because of this clinical importance, topographic anatomy of the suprameatal spine and depression was studied on Anatolian skulls. In all, 363 male and 231 female skulls were studied. The most prevalent type of suprameatal spine resembled a crest and was found in both sexes on the right (77.6%) and left (80%) sides. The absence of a suprameatal depression was significantly higher in females (right 9.1%; left 8.7%) than in males (right 1.7%; left 2.5%). Suprameatal depressions were mostly shallow in female subjects, but were mostly observed in males to be at a medium depth or deep.     

Paget's disease and sensori-neural deafness: temporal bone histopathology of Paget's disease

Four cases with Paget's disease of the temporal bone are presented to illustrate the pathogenesis of the associated deafness. One case illustrates the combination of severe deafness due to bilateral otosclerosis with probably asymptomatic bilateral Paget's disease. One case with advanced Paget's disease presents features to explain early stages of sensori-neural deafness before actual cellular invasion of the inner ear. One case of profound deafness due to Paget's disease presents a different stage of cellular invasion of the inner ear by the disease on each side. One case illustrates invasion of the internal auditory meatus by Paget's disease with infiltration of the acoustic division of the nerve and profound deafness.