Biomedical subjects

K Donath

Publications and source records attributed to K Donath.

At least 37 records · Page 2Linked to original sources

PubMed1999

Unusual choristoma of the parotid gland in a girl. A possible trichoadenoma.

An 8-year-old girl had a painless circumscribed nodule in the right parotid gland for 4 weeks. A tumour (1.3 cm diameter) within the salivary gland parenchyma showed small cystic spaces with horn-like material macroscopically. The tumour tissue contained solid squamous cell formations and cystic spaces limited by multilayered squamous epithelium and covered by layers of ortho- and parakeratotic cells. The cystic spaces contained keratotic lamellae. In some areas pin-like epithelial proliferations were seen. All epithelial cells were characterized by uniform nuclei, and no atypical mitoses were seen. Keratinizated masses with partial calcification were occasionally located in the interstitial tissue and replaced by multinucleated giant cells. The tumour was classified as a choristoma and resembled a trichoadenoma. The ectodermally derived oral and salivary gland epithelium may be the source of skin-like or adnexal tumours.

Adenoma↗

PubMed1999

Lipomatous pleomorphic adenoma of the parotid gland. Classification of lipomatous tissue in salivary glands.

Lipomatous pleomorphic adenoma is an unusual subtype with a lipomatous stromal component of more than 90% of the tumour tissue. This special type of pleomorphic adenoma must be distinguished from other types of lipomatous tumours or non-tumourous lipomatosis of the salivary glands. Until now only two cases of lipomatous pleomorphic adenoma have been reported in the literature. We report of a 36-year old woman who developed a well circumscribed nodule measuring 3.5 x 2.5 x 2 cm in the right parotid gland. The cut surface was grey-yellowish. Histologically, more than 90% of the tumour tissue was fatty tissue with univacuolar adipocytes. The pleomorphic epithelial elements were duct-like cells forming small lumina and spindle-shaped myoepithelial cell with surrounding mucoid stroma. Components of pleomorphic adenoma were intermingled with mature adipose tissue which was more concentrated in the central portion of the adenoma. Some compressed epithelial cords in the adipose tissue formed a septa-like pattern. The differential diagnosis to other lipomatous tumours (lipoadenoma, lipoma) and to non-tumourous interstitial lipomatosis as well as the possible pathogenesis as metaplastic change or epithelial-mesenchymal transdifferentiation are discussed.

Adenoma, Pleomorphic↗

PubMed1999

A comparative study of sonographic and histopathologic findings of tumorous lesions in the parotid gland.

OBJECTIVE: The purpose of this study was to clarify which histopathologic features are visualized on sonograms by comparing sonomorphologic and histopathologic analyses of parotid tumorous lesions on the same plane. STUDY DESIGN: Boundaries, shapes, echo intensity level, distribution of internal echoes, and acoustic enhancement on sonograms of 86 parotid tumorous lesions were retrospectively compared with the histopathologic findings. RESULTS: Unclear boundaries on sonograms corresponded to abundant connective tissue with scattered tumor cell nests. Polygonal shapes on sonograms were revealed to represent tumor cell infiltration on histopathologic sections. The "very hypoechoic" lesions showed significantly high ratio of cystic areas (P < .05) in Warthin tumor. The weakly hyperechoic structures on sonograms were connective tissue, hyaline, and necrotic and keratinized materials. Attenuated posterior echoes were observed in malignant tumors with abundant connective tissue and metaplastic bone formation. CONCLUSIONS: To facilitate correct sonographic diagnosis, it is important to ascertain the correlation between sonomorphology and histopathology.

Adolescent↗

PubMed1999

Statistical study for sonographic differential diagnosis of tumorous lesions in the parotid gland.

OBJECTIVE: The purpose of this study was to clarify characteristic sonomorphologic features of parotid lesions statistically and to propose new criteria for the differential diagnosis. STUDY DESIGN: Eighty-six tumorous lesions were analyzed with regard to the following sonomorphologic features: boundary, shape, echo intensity level, distribution of internal echoes, and acoustic enhancement. Stepwise polychotomous logistic regression analysis was performed to assess characteristic sonographic features. As dependent variables, we used "pleomorphic adenoma," "Warthin tumor," "malignant tumors" and "other benign lesions"; as predictor variables, we used the aforementioned sonomorphologic features. Proportion of the occurrence of each dependent variable was calculated. RESULTS: Lobular shape and homogeneous internal echoes predicted pleomorphic adenoma. A lesion with multiple anechoic areas would be Warthin tumor with very high sensitivity. Malignant tumors showed either heterogeneous internal echoes without characteristic structures or polygonal shape. CONCLUSIONS: These sonomorphologic features should be observed to make more exact differential diagnoses for operation and therapy planning.

Acoustics↗

PubMed1999

Characteristic features of trabecular bone in edentulous maxillae.

Following tooth loss, the maxillary alveolar ridge is affected by extensive resorption and its cancellous bone substance undergoes intense remodeling processes. This is particularly important for endosseous implant surgery as the primary stability and thus the prognosis of endosseous implants depends on the cancellous bone density and structure of the alveolar ridge. To analyze the structure of alveolar trabecular bone, 156 sections were obtained from 52 edentulous maxillae (29 female, 23 male; mean age: 72.5 years) from the lateral incisor, first premolar, and first molar regions. The structural histomorphometric analysis was performed on cancellous bone of the section surfaces using semiautomatic image analysis. The following parameters were measured: trabecular bone volume, trabecular number, trabecular thickness, trabecular plate separation and trabecular interconnection. All examined parameters showed an extreme range of variation. A difference of more than 45% between the highest (= 51.93%) and the lowest (= 6.73%) trabecular bone volumes was found. Furthermore, the measurements showed that trabecular bone volume, thickness and number were distinctly lower in the molar region than in the incisal and premolar regions. Significant sex-specific differences were found in all investigated regions, female maxillae showing a smaller amount and a lower connectivity of cancellous bone than male maxillae.

Adult↗

PubMed1999

[Orthotopic cartilage transplantation. Morphologic, angiography and histochemical studies of the vitality of free septum transplants].

Orthotopic cartilage transplantation is a technique frequently used in modern septal surgery. The prerequisite for a stable long-term result is viability of the transplanted cartilage. Therefore, we studied the healing process histologically, angiographically, and histochemically. We found a characteristic picture. Due to chondronal structure of the cartilage, the healing process varied in time and location. Reintegration took place by chondroneogenesis, commencing at the inner perichondrium. Reintegration depended directly on the distance of the cartilage cells to the surrounding vessels. Histochemically, we found an intact respiratory chain in the mitochondria and thus, we were able to demonstrate the preservation of viability in orthotopic transplanted cartilage.

Angiography↗

PubMed1999

Bone-tissue formation and integration of titanium implants: an evaluation with newly developed enzyme and immunohistochemical techniques.

BACKGROUND: Examination of the tissue surrounding retrieved implants involve routine investigations on cut and ground sections. Undecalcified sections with implants in situ are histologically stained followed by qualitative and quantitative observations of the tissue response to the implants by light microscopy. PURPOSE: A novel technique that allows for the accurate definition and quantification of enzymes involved in bone formation (alkaline phosphatase) and resorption (acid phosphatase) in the tissue is presented. MATERIALS AND METHODS: Commercially pure titanium and titanium alloy (Ti6Al4V) implants were retrieved after 6 and 12 weeks of healing in rabbit bone. In addition, 4-week specimens from commercially pure titanium bone harvest chambers placed in rabbit bone were used. Undecalcified cut and ground sections were produced and evaluated with enzyme and immunohistochemical staining techniques. RESULTS: The titanium implants retrieved after 6 weeks of insertion in rabbit bone revealed a higher activity of both alkaline phosphatase and acid phosphatase activity compared to the implants followed for 12 months. The former samples revealed ongoing bone-tissue remodeling in the interface, whereas the latter ones showed steady-state bone conditions. Applying the new technique allowed for investigation of various bone proteins present in the tissue that had formed inside titanium canals of harvest chambers at various times of follow-up. CONCLUSIONS: The combination of routine histologic stainings with enzyme and immunohistochemical technique of cut and ground specimens is a valuable tool in the investigations of retrieved implants from humans and animals. This novel technique now may be used to describe the state of bone regeneration in the interface zone associated with implant research.

Acid Phosphatase↗

PubMed1999

Formation of bone around titanium implants placed into zero wall defects: pilot project using reinforced e-PTFE membrane and autogenous bone grafts.

BACKGROUND: Guided bone regeneration (GBR) frequently is used to augment implants with various types of bone defects. The defects often are grafted with different materials, yet there is insufficient evidence that these materials enhance bone-to-implant contacts. PURPOSE: The purpose of this pilot project was to test the principle of GBR to promote bone formation adjacent to commercially pure titanium implants placed within zero-wall defects. Histologic and histomorphometric measurements were used to evaluate new bone formation. MATERIALS AND METHODS: Under appropriate anesthesia, deep, wide defects were created within the mandibles of two large dogs. Buccolingual bone was removed to the depth of the defects leaving only the mesial and distal walls. Of the eight implants placed, three were augmented with titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) barriers and autogenous bone chips. Three sites were augmented with barrier membranes only, and two sites were not augmented or grafted and served as controls. Seven months after surgery the dogs were sacrificed and block sections were taken for histologic evaluation. RESULTS: Histologic and histomorphometric measurements were used to evaluate new bone formation. Results from this evaluation revealed bone formation at the membrane-only sites and the membrane-plus-bone grafted sites. The bone grafts were completely incorporated by the newly formed marginal compact bone. For all treated sites, there was poor bone-to-implant contact. Histomorphometric measurements showed a trend toward greater bone formation at membrane-treated sites compared with control sites. However, autogenous bone grafting did not seem to affect the amount of newly regenerated bone. CONCLUSIONS: Within the limits of this pilot project, findings show trends toward bone healing, indicating constant and enhanced bone regeneration over the exposed implant. Bone contact to the implant surface generally was poor.

Animals↗

PubMed1998

[Differential diagnosis of squamous epithelial carcinoma of the salivary glands].

Primary squamous cell carcinomas (SCC) of the salivary glands are localized predominantly in the major salivary glands and must be distinguished from metastases of extraglandular SCC of the skin, especially the head and neck area. Squamous cell metaplasia in non-tumourous diseases of the salivary gland (e.g. necrotizing sialometaplasia) as well as in benign or malignant salivary gland tumours (e.g. metaplastic Warthin tumour) can simulate SCC. Other differential diagnostic problems are the structural variants of SCC which develop predominantly in the minor salivary glands, but not in the major salivary glands. Special types include the very rare adenoid SCC with pseudoglandular structures as the result of acantholysis, the biphasic adenosquamous carcinoma with differentiation as SCC and adenocarcinoma, the biphasic basaloid squamous carcinoma with a structure as SCC and solid basaloid carcinoma (analogous to the solid type of adenoid-cystic carcinoma) and the poorly differentiated mucoepidermoid carcinoma (grade III) with biphasic structure of undifferentiated epidermoid and intermediate cells as well as inclusion of small groups of mucous-producing goblet cells. The differential diagnostic criteria are analysed concerning prognosis and treatment.

Carcinoma, Squamous Cell↗

PubMed1998

[Juvenile pleomorphic parotid adenoma of embryonal structure].

Juvenile pleomorphic adenoma of the parotid gland represents an extremely rare tumour entity and is comparable to congenital tumours of the salivary glands concerning its embryonal structure. The clinical detection of the tumour in a 7-year-old girl does not exclude that the tumour had developed either earlier or immediately after the birth. The high cellularity and the evidence of primitive epithelial and myoepithelial cellular structures do not justify its classification as a malignant tumour. However the presence of embryonal tissue structures associated with the end of the third month of embryogenesis is characterized by more solid cell formations in partly verticulate arrangement. The absence of further differentiation into lobular structures and differentiated duct or acinic cell formations may be due to cell arrest. Differential diagnosis of juvenile pleomorphic adenoma must distinguished it from other congenital salivary gland tumours (e.g. congenital basal cell adenoma, hybrid basal cell adenoma-adenoid cystic carcinoma, sialoblastoma, salivary gland anlage tumour.

Adenoma, Pleomorphic↗

PubMed1998

[Cranial and cervical chordomas. A differential diagnostic problem].

Cranial and cervical chordomas can spread by para- or retropharyngeal extension up to the region of the salivary glands or the jaw and may simulate a tumor of the salivary glands or jaw. In occasional cases, because the tumors often expand slowly, months or years may pass between the first clinical symptoms and diagnosis. Diagnostic problems exist in differentiating these chordomas from pleomorphic adenoma, mucinous carcinoma, or chondrosarcoma. Ten relevant observations of typical cranial and cervical chordomas (Salivary Gland Register Hamburg 1965-1996) were analyzed more closely by pathohistological and immunohistochemical means. The exact diagnosis is based upon the evidence of blown-up, bubble-like ("physaliform") cells which contain mucus drops in a vacuolized cytoplasm and are surrounded by extensive areas of mucoid mucus. The pattern of immunohistochemistry is characterized by the multifold expression of cytokeratin, vimentin, and EMA. The differential diagnosis is discussed with reference to further types of chordoma (chondroid chordoma, dedifferentiated chordoma with spindle cell sarcomatous transformation), chondrosarcoma, pleomorphic adenoma, and mucus-producing carcinoma.

Adult↗

PubMed1998

[Clear cell odontogenic carcinoma in connection with squamous epithelial carcinoma. Case report and review of the literature].

One case of a newly described, rare odontogenic tumor is reported. A literature review of 19 cases lends support to the odontogenic origin and metastatic capability, both regionally and distantly, of the clear cell odontogenic tumor. We conclude that this tumor is malignant, with a tendency to recur locally after surgery. It requires an aggressive surgical approach and should be referred to as a clear cell odontogenic carcinoma. In our patient we saw a clear cell odontogenic carcinoma and a squamous cell carcinoma, both with regional lymph node metastasis. The histological differentiation of this type of tumor from other clear cell tumors is difficult.

Adenocarcinoma, Clear Cell↗

PubMed1998

Sonographic analysis of recurrent parotitis in children: a comparative study with sialographic findings.

OBJECTIVE: The sonographic features of recurrent parotitis in children were studied to clarify a relationship between sonographic and sialographic findings in this disease. STUDY DESIGN: Twenty-one glands (7 on follow-up) were examined by 7.5 MHz ultrasonography and sialography. Echo intensity level, distribution of the internal echoes, and size of hypoechoic areas were compared with the size of punctate shadows on the sialograms. Twenty other histopathologic specimens were analyzed to investigate the entity of hypoechoic areas. RESULTS: Sonography showed hypoechoic, heterogeneous internal echoes, the level of which increased as the punctate shadows enlarged. Hypoechoic areas, all of which were larger than the sialographic punctate shadows, were observed in 62% of the glands. Histopathologic analysis suggests that these hypoechoic areas represent dilated peripheral ducts with lymphocytic infiltration. Sonography was likely to detect changes over time more sensitively than sialography. CONCLUSIONS: Sonography should be performed as the test of first choice, both in the primary and follow-up stages, in cases of recurrent parotitis in children.

Adolescent↗

PubMed1998

Histogenesis and development of membranous basal cell adenoma.

The histogenesis of salivary gland tumors remains controversial. A histologic and immunohistochemical study was carried out on 12 cases of membranous basal cell adenoma in the salivary glands to investigate its histogenesis and development. In 4 cases, multiple focal proliferations of striated ducts in the surrounding salivary gland, which were conspicuous, allowed tracing of the development of the tumors from their origin. The earliest changes were characterized by hyperplasia of the basal cells of striated ducts. Continuous ductal proliferation led to the formation of microadenomas. The observations suggest that proliferating basal cells of striated ducts apparently participate in and play a main role in the histogenesis of some membranous basal cell adenomas of the salivary glands.

Adenoma↗

PubMed1998

Bovine hydroxyapatite for maxillary sinus grafting: comparative histomorphometric findings in sheep.

This experimental study in animals examines the value of bovine hydroxyapatite as grafting material in one-stage sinus lift procedure. The Schneiderian membrane was elevated from extraorally in 54 sinuses of 27 adult female mountain sheep. Two titanium plasma-flame-spray coated cylindrical implants were placed in each sinus in the same session. In 2 groups of 18 sinuses each, the subantral hollow space was filled with bovine hydroxyapatite and autogenous cancellous bone from the iliac crest, respectively. Eighteen sinuses that were left empty served as a control group. Polyfluorochrome sequential labelling (tetracycline, calcein green, alizarin complexon) was carried out 4 weeks postoperatively, 2 weeks before the animals were sacrificed, and halfway through the observation period to assess new bone formation. The selected observation periods were 12 weeks, 16 weeks, and 26 weeks. Six sinuses per observation period and test group were available for histologic evaluation. All implants showed favourable osseointegration into local bone. New bone formation was observed in a triangular area bound by the implant surface, the local buccal antral wall, and submucous connective tissue in all implants. Bovine hydroxyapatite adjacent to local bone was mainly surrounded by bone tissue. There was a great variation in the extent of bony sheathing of the hydroxyapatite particles, irrespective of the animals' survival time. Macrophages were found around HA particles that were not surrounded by bone as well as on free implant surfaces. The mean length of the bone-implant bond was 3.86 mm in the group of empty sinuses, 4.87 mm in the group augmented with hydroxyapatite, and 5.66 mm in the group augmented with autogenous cancellous bone. During the observation period, the relative length of bone in direct contact with the implant surface increased from 20.0% to 25.1% in the control group, from 30.4% to 35.5% in the group treated with autogenous cancellous bone, and from 27.4% to 34.7% in the HA group. Autogenous cancellous bone showed a significantly greater bone-implant contact than did the control group (P = 0.0004) and the HA group (P = 0.0499). When the apical implant portions were examined separately, both HA (P = 0.006) and autogenous cancellous bone (P = 0.005) showed a significantly better bone-implant bond than did the control group.

Animals↗

PubMed1998

[Histopathogenesis of chronic sialectatic parotitis as precursor of myoepithelial sialadenitis lesion (Sjögren syndrome)].

BACKGROUND: Chronic sialectatic parotitis (CSP) is classified as a characteristic form of chronic recurrent parotitis the etiology and pathogenesis of which still remains unclear. The multiplicity of different therapeutic advices, especially the permanent failure of antibiotic treatment, underlines the lack of an appropriate causal therapy. CASE REPORT: Detailed histopathological investigations of an 41-year old woman were possible over a seven-year period. These follow-up observations enabled clarification of the histopathogenesis of CSP by means of immunohistochemistry. RESULTS: During the course and development of CSP different stages can be observed: The initial phase is characterised by mild infiltration of B-lymphocytes (CD20, CD45 R) and plasma cells in the environment of ectatic ducts. Progredient stages show neogenetic lymph follicles periductular as well as metaplasia of the ductal epithelium. Terminal phases of CSP are characterised by near-total lymphatic transformation of parenchyma, follicular lymphatic hyperplasia (KiM4) and myoepithelial proliferation. In this phase myoepithelial sialadenitis (MESA, i.e. benign lymphoepithelial lesion, possibly part of Sjögren's syndrome) develops. Beyond it low grade non-Hodgkin's lymphoma of the MALT-Type of the submandibular gland occurred finally. CONCLUSIONS: CSP presents as a precursor of MESA. Immunohistological detection of follicular dentritic network (KiM4) within extensive lymphatic hyperplasia periductular demonstrates overshooting humoral immune reaction of B-lymphocytes. Hence, CSP should be classified with regard to pathogenesis as an immunopathological disorder of the MALT system.

Adult↗

PubMed1998

Membranous basal cell adenoma of the salivary gland: a clinicopathologic study of 12 cases.

Twelve cases with membranous basal cell adenoma of the salivary gland were analysed clinicopathologically. Its histology was characterized by palisading of peripheral cells and an excessive hyaline basal membrane. The differential diagnosis involved the solid variant of basal cell adenoma, basal cell adenocarcinoma, solid subtype of adenoid cystic carcinoma and basaloid squamous cell carcinoma. Four cases had coexisting dermal cylindromas of the scalp. Screening for skin lesions of the scalp or other locations is suggested. In 8 cases, the tumors demonstrated multifocal origin. Total parotidectomy rather than superficial parotidectomy is suggested to avoid the recurrence of the tumor. One case showed malignant transformation and cervical lymph node metastases. A close follow-up after treatment is necessary.

Adenoma↗

PubMed1998

Glandular odontogenic cyst (sialo-odontogenic cyst): report of two cases and literature review of 45 previously reported cases.

The clinical, radiological, histopathological and immunohistochemical (cytokeratin) features of two cases of glandular odontogenic cyst (GOC) are presented and discussed in a review of 45 cases of GOC hitherto reported. Of cases with available information, 34 occurred in the mandible and 6 in the maxilla; the male:female ratio was 19:28, and the mean age was 46.7 years in males and 50.0 years in females. Six cysts recurred once after 2-8 years (mean 2 years 8 months) and 2 (5.3%) recurred twice after 2 and 5 years and after 3 and 5 years, respectively, giving a rate of recurrence of 21%. The identification of osteodentin in one of the present cases and the co-expression of cytokeratins (CK) 13, 19 and 8 strongly support the concept of odontogenic differentiation in the GOC. Careful surgical removal of the lesion succeeded by a 5-year follow-up period is recommended.

Adult↗