Two cases are presented. The first of them involved a histological study of facial canal dehiscence with a retraction pocket of the tympanic membrane of the right ear. Prolapse of the facial nerve from its facial canal was revealed; the facial nerve was in contact with the stapes and retraction pocket. Computer-assisted three-dimensional reconstruction was performed with histological sections of the temporal bone. The second case involved malformation of the stapes suprastructure and fixation of footplate, with subsequent prolapse of the facial nerve, which covered the footplate. Our approach to the surgery consisted of gently retracting the prolapsed facial nerve, then making a monitoring hole in the visible portion of the footplate, following down the fracture and removing the stapes superstructure. A piston prosthesis was inserted. After surgery, the patient suffered from slight facial paresis at H-B II level. The functions of facial nerve and hearing were normal after six months. The surgeon should bear in mind that procedures performed in the middle ear have a high potential to traumatize or damage the facial nerve at the site of dehiscence. We conclude that stapes surgery in patients with significant facial nerve prolapse can be performed safely, with good hearing results, in the hands of an experienced surgeon.

A case of a 63-year-old man with a swelling lasting 2 years in the left infraauricular area is reported. Examination by fine needle aspiration cytology raised suspicion of mucoepidermoid or adenoid cystic carcinoma of the parotid gland and an excision was recommended. The lateral parotidectomy specimen showed a poorly circumscribed gelatinous tumor measuring 15 mm in diameter within the parotid gland tissue. Microscopically, the lesion featured large pools of mucin containing clusters of tumor cells with little atypia and low mitotic activity. Immunohistochemically, the tumor cells showed expression of epithelial markers and of both estrogen and progesterone receptors. Left lateral neck dissection revealed massive lymphogenous dissemination of the tumor. Retrospective analysis of a skin biopsy from the same anatomic area performed 8 years prior to parotid neoplasm displayed a tumor with identical microscopic appearance and immunohistochemical profile (additionally performed) which was, however, misdiagnosed as a benign lesion. The diagnosis of recurrent primary mucinous carcinoma of the skin infiltrating the parotid gland was established. The patient underwent radiotherapy and has been 3 years free of disease. The differential diagnostics of this rare tumor is discussed.

Three case studies demonstrate current views on the diagnosing and treatment of thrombosis of the sigmoid sinus. The factors causing thrombosis are of infectious and non-infectious nature. The cause of infectious thrombosis is acute mastoiditis which is frequent in children and is usually linked with a state of hypercoagulation, or a long-term chronic middle ear inflammation with cholesteatoma, especially in adult patients with an immune system disorder or diabetes mellitus. Non-infectious thrombosis primarily develops as a result of disturbed coagulation and prevailingly affects young women, female smokers, pregnant women or women taking hormonal contraception. The treatment of inflammatory otogenous thrombosis of sigmoid sinus is based on the administration of antibiotics and surgical sanitation of the temporal bone,administration of anticoagulation medication and surgical treatment of the thrombus is still an issue. On the other hand, anticoagulation therapy is a key element in non-infectious sigmoid sinus thromboses. Targeted detection of inborn or acquired thrombophilic state is necessary in all patients with sigmoid sinus thrombosis.

A 62-year-old man was referred to the Department of Dentistry because of ultrasonographic finding of "cystoid lesion with relationship to right parotid gland". During operation, a tumor mass without any relationship to parotid gland but attached to the right internal carotid artery was found. Grossly, the tumor was well circumscribed, spheric, measuring 40 mm in diameter; it was of solid, firm appearance and tan-to-white color on cross section. Microscopically, the tumor cells were round to spindle-shaped with vesicular nuclei and eosinophilic cytoplasm, arranged in fascicular pattern. Immunohistochemically, the cells expressed vimentin, CD 34, smooth muscle actin, and bcl-2 protein. On the basis of microscopical appearance and results of immunohistochemistry, the diagnosis of solitary fibrous tumor (cellular variant) was established. One year after resection, the patient is free of disease. A new concept of this uncommon mesenchymal tumor is discussed.

A case of a 24-year-old woman with a 6 weeks lasting nodule of the right margin of the tongue is described. The nodule was 20 mm in diameter and showed surface ulceration. The diagnosis of low grade myofibroblastic sarcoma was supported by histological, immunohistochemical and electronmicroscopic examination. Although the tumor resection was not complete, the patient is free of disease 1 year after operation. The differential diagnostics of low grade myofibroblastic sarcoma is discussed.

Objective To investigate the temporal bone with a malformed stapes in VACTERLS association. Study Design The study design was a case report, histopathology of the temporal bone, and three-dimensional reconstruction of the ossicles and cochlea. Setting The study was carried out in the Temporal Bone Bank at Charles University, Hradec Králové, on a case from Temporal Bone Foundation, Boston. Patient A 1540-g, 41-cm female neonate with VACTERLS association, histopathology of the temporal bone, and three-dimensional reconstruction of the middle ear ossicles and cochlea. Results The posterior part of the footplate was missing, and the posterior crura of the stapes was not connected to the footplate but found freely suspended in the sinus tympani. Conclusion Computer-assisted three-dimensional reconstruction was performed from histologic sections of the temporal bone removed from a case of VACTERLS association. The reconstruction included structures such as the bony labyrinth and the middle ear ossicles. The abnormality observed in the reconstruction included the mislocation of the stapes and a shortened footplate.

Apoptosis was studied using temporal bones from three fetuses representing different times of gestation and from three neonates. Paraffin-embedded sections 20-microm thick were studied using the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling method based on 3'-end-labeling of fragmented DNA. Phenotyping of the immune cells was performed using regular monoclonal antibodies. In the bone marrow the granulocyte series dominated and the number of cells in the macrophage series was noticeably fewer, with apoptotic cells occurring in both. In the embryonic mesenchyme, solitary apoptotic cells occurred in all locations in both the fetuses and neonates. Apoptosis is a basic factor in the regression of embryonal mesenchyme, but may not be preprogrammed. Basic scientific data obtained from modified tissue cultures show that mechanical forces cause cells to switch between different genetic programs. It is suggested that the act of swallowing causes periodic changes in the amniotic fluid pressure and provides the necessary force for regression of the mesenchyme by apoptosis.

OBJECTIVES: Liver regeneration is influenced by cholesterol and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA-reductase). HMG-CoA-reductase is a key enzyme for cholesterol synthesis. Recent studies have shown that inhibitors of HMG-CoA-reductase improve liver functions after 67% partial hepatectomy (PH).METHODS: Male Wistar rats (W) and Prague hereditary hypercholesterolemic rats (PHHC) were used. Aqua pro injectione (AI) or pravastatin (prava; 1 mg/kg) was administered orally once daily. Group l: W, standard diet (SD) + AI; group 2: W, SD + prava; group 3: W, cholesterol-enriched diet (chol) + AI; group 4: PHHC, chol + AI; group 5: PHHC, chol + prava. After 27 d, PH was performed in all groups.RESULTS: Groups fed chol before PH had significantly higher liver triacylglycerol content (group 3: 25.8 +/- 2.6 mg/g of liver weight; group 4: 16.0 +/- 1.0 of liver weight; group 5: 22.0 +/- 1.0 of liver weight) than did the groups fed SD (group 1: 6.1 +/- 0.5; group 2: 5.9 +/- 0.7). Liver DNA synthesis after PH was significantly lower in chol-fed groups (group 3: 561 +/- 78; group 4: 472 +/- 92) than in SD-fed groups (group 1: 1645 +/- 574; group 2: 2935 +/- 1298), except the chol-fed PHHC given prava (group 5: 3230 +/- 527).CONCLUSIONS: In prava-treated rats, the induction of HMG-CoA activity overcame the inhibitory capability of pravastatin. The induction of HMG-CoA-reductase activity had a stimulatory effect on the initiation of liver regeneration. (C) Elsevier Science Inc. 2002.

Microscopic sections of 37 temporal bones from 22 foetuses were examined, five with renal agenesis, six with Potter's sequence without renal agenesis and two with mild kidney pathology. Every tenth section containing the stapes were used for measuring the volume of mesenchymal tissue in the middle ear cavity. At 5% significance level, foetuses with serious renal pathology had more mesenchymal tissue in the middle ear cavity than a control group of nine foetuses with no renal or urinary tract abnormality.

An unusual case of acute purulent thyroiditis in a 45-year-old man forming a large abscess in the left lobe of the thyroid gland is described. It perforated the capsule at the posterior wall of the thyroid, causing extensive retropharyngeal and retrotracheal abscesses. The patient was treated with broad-spectrum antibiotics and surgical excision of the infected tissues. He has remained well one year after the operation.

Three cases of the periprosthetic breast capsules showing typical features of synovial metaplasia are presented. The histological picture is characterized by the presence of cellular layer mimicking synovial membrane. These elements are devoid of basement membrane, otherwise, nevertheless, they strongly resemble single- or multilayered epithelium. Focally, the differentiation towards giant multinucleated cells is noted. Immunohistochemical profile, as well as the ultrastructure of the cells, confirms their histiocytic origin with advanced differentiation towards elements of the synovial membrane. These histological features are referred to as synovial or synovial-like metaplasia. They are found in considerable fraction of textured breast implant capsules. The pathogenesis remains uncertain; however, similar picture was observed in other locations in association with prolonged or repeated action of mechanical forces. Thus, movement of the implant in situ is the most probable trigger of synovial metaplasia.

The temporal bones from fetuses with known autosomal trisomy syndromes were examined histopathologically after spontaneous or induced abortions. Fetal ages dated from the 17th to the 24th week of pregnancy. In all, 17 temporal bones from nine fetuses were studied and included seven cases of Down's syndrome and two of Edwards' syndrome. Temporal bones from fetuses with Down's syndrome had more abnormalities of the external and middle ears than of the inner ear. The bones from the fetuses with Edwards' syndrome showed abnormalities of the external or middle ear and retarded development of the inner ear (failed ossification of the otic capsule and unformed organ of Corti).

The authors evaluate the group of 25 patients suffering from malignant melanoma in head and neck region. Patients were treated on ENT clinic in Hradec Králové during 1961-1991. The authors describe the localization of malignant melanoma, the process of therapy and the surviving of patients. The contemporary opinions are discussed for possibilities of therapy.