Biomedical subjects
Publications and source records attributed to M Gebhart.
Three cases of pigmented villonodular synovitis treated in recent years are described. One case presents a malignant transformation and raises the question of the benign character of these lesions. The therapeutic options are considered as well as the need for a larger series of patients to define therapeutic strategy.
Pigmented dermatofibrosarcoma protuberans (Bednar tumor) is a rare neoplasm accounting for approximately 1-5% of all cases of dermatofibrosarcoma protuberans. The majority occurs on the trunk, and the remainders are more or less equally distributed in the upper and lower extremities and the head and neck. Microscopically it is characterized by spindled cells arranged in a tight storiform pattern and admixed with a small population of melanin-containing dendritic cells. The dendritic cells are the primary feature that distinguish this lesion from conventional dermatofibrosarcoma protuberans. We report here a case of Bednar tumor occurring on the dorsal aspect of the foot in a young female.
PURPOSE: The aim of our study is to investigate the in vitro effects of plant lectins, galectins and neoglycoconjugates on the proliferation of three human sarcoma cell lines. METHODS: Proliferation was assessed by means of the tetrazolium derivative reduction (MTT) assay. In addition, glycohistochemistry was used to make visible the plant-lectin-specific binding sites; the intensity of the lectin binding pattern was quantified by means of image analysis. RESULTS: Depending on the cell lines, the staining intensity and the percentage of labelled cells were different. With respect to growth modulation, the cell lines also responded differently to the probes used. Besides a predominant inhibitory effect elicited by the probes at 50 microg/ml, dose-dependent effects, including growth stimulation, were detectable in several instances. These effects relate to the animal galectins tested and several neoglycoconjugates, e.g. the lactose- and blood-group-A-trisaccharide-bearing probes. CONCLUSIONS: Endogenous lectins and lectin-reactive cellular glycoconjugates can apparently affect the regulation of the growth of human sarcoma cells. We suggest that these results are relevant for further histopathological monitoring in correlation with prognosis and in vitro assays to reveal possible clinical applications.
First described by LERY and JOANNY in 1992, melorrheostosis is an uncommon linear hyperostosis of unknown aetiology, which may be associated with soft tissures changes. Although all bones may be affected, cranio-facial involvement is very rare. Only six such cases have been found in the literature. This report describes a case of cranio-facial and left humeral melorrheostosis with symptomatic radial nerve involvement. Resection of the melorrheostotic bone was performed because of involvement of the radial nerve.
Extra-abdominal desmoid tumors are locally aggressive benign soft tissue tumors arising from the connective tissue of muscle and overlying fascia or aponeuroses. Location around the hip occurs in about 10% of all desmoid tumors. The authors report the development of a desmoid tumor around the hip 45 months after implantation of a total hip prosthesis. Endocrine and physical factors seem to play an important role in the development of the disease. Moreover, an association has been reported between trauma and desmoid tumor. Desmoid tumors developing around silicon implants have also been described. However, no association between hip prostheses and desmoid tumors has been published in the world literature. Although soft tissue tumors induced by metallic implants have been observed clinically, we still seek a coherent explanation for the exact pathogenesis.
The authors propose a simple and practical method to measure radiologically the angle of ante- or retroversion of the acetabular cup using a goniometer. It only necessitates an anteroposterior radiograph centered on the femoral head and another one centered on the public symphysis. Special x ray equipment, compass, conversion table, mathematical formulas, or a pocket calculator are not required. The opening of the prosthetic cup is projected on the film as an ellipse. According to the rules of descriptive geometry, the true size of the angle of anteversion is easily obtained. The geometric constructions consist in drawing four lines. The adequate positioning on a hip radiograph of the protractor, drawn on the goniometer, permits the direct reading of the true and planar anteversion angles of the cup.
Little is known about the regulation of sarcoma proliferation by hormones and/or growth factors. We therefore characterised the in vitro proliferative influence on eight sarcoma cell lines of the platelet-derived growth factor, the insulin-like growth factor 1, triiodothyronine, the epidermal growth factor, the luteinising-hormone-releasing hormone, progesterone, gastrin and 17 beta-oestradiol. The influence of the different factors on the proliferation of sarcoma cell lines was measured by the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Two culture media were studied: (1) a nutritionally poor medium containing 2% of fetal calf serum and (2) a nutritionally rich one containing 5% or 10% FCS both with and without the addition of non-essential amino acids. The results were analysed either by conventional statistical analyses or by a classification method based on a decision-tree approach developed in Machine Learning. This latter method was also compared to other classifiers (such as logistic regression and k nearest neighbours) with respect to its accuracy of classification. Monovariate statistical analysis showed that each of the eight cell lines exhibited sensitivity to at least one factor, and each factor significantly modified the proliferation of five or six of the eight cell lines under study. Of these eight lines one of fibrosarcoma origin was the most "factor-sensitive". Decision-tree-related data analysis enabled the specific pattern of factor sensitivity to be characterised for the three histological types of cell line under study. The effects of hormone and growth factors are significantly influenced by the type of culture medium used. The method used appeared to be an accurate classifier for the kind of data analysed. Sarcoma proliferation can be modulated, at least in vitro, by various hormones and growth factors, and the proliferation of each histopathological type exhibited a distinct sensitivity to different hormone and/or growth-factors.
Paget's disease is uncommon in patients younger than 50 years of age. Multifocal giant cell tumors arising in bone affected by Paget's disease have been described previously in 37 cases. A case of a 38-year-old man with polyostotic Paget's disease and multifocal giant cell tumors responsive to steroid therapy is presented.
Intramuscular myxoma is a rare, benign, mesenchymal tumour. It contains fibroblast-like, histiocyt-like and myofibroblast-like cells in a myxoid material. These tumours occur in adults between 40 and 60 years with a predilection for women (70%). The incidence varies between 0.10 and 0.13/100.000. They may occur as an independent lesion or in conjunction with fibrous dysplasia or Albright syndrome. Although only circumstantial features have linked fibrous dysplasia and myxoma, the concept of a basic metabolic error of both tissues during initial growth period has been proposed. There are no specific clinical manifestations of this tumour. Although MRI offers the best imaging approach in terms of determination of the local extension of the tumour and its fatty texture, the differential diagnosis between intramuscular myxoma and myxoid degenerescence of a liposarcoma must be considered. The diagnosis is always made after microscopic examination. Local excision with histological margins free of tumour provides excellent local control without recurrence. The case of a patient presenting this rare tumour is presented. A thorough survey of the literature was done.
Camurati-Engelmann disease is an uncommon condition, radiologically characterized by symmetric diaphyseal sclerosis involving the tubular bones. Clinical features include limb pain, muscle weakness, waddling gait and sometimes deafness. The evaluation is made by conjunction of radiographic and scintigraphic data. Corticosteroids and analgesics improve the quality of life, decrease the pain but do not alter the course of the disease. The evolution is unpredictable. The history of a 23 year old male with such a disorder is presented hereafter. His clinical course shows a very good response to the administration of corticosteroids, whereas no improvement is observed as far as the radiographic and isotopic features are concerned.
Between 1986 and 1993, 18 patients with complete or impending fractures of the humerus were treated using Hacketall rods in association with semi-liquid methylmetacrylate after excision of the metastatic lesion. Methylmetacrylate was always injected proximally and distally to the curetted bone through drill holes. Fourteen patients had a pathological fracture and four presented with an impending lesion. The mean age at time of surgery was 62 years (range: 42-83). The primary tumour was a breast carcinoma in 10 cases, bronchogenic squamous cell carcinoma in three cases and hypernephroma, multiple myeloma, malignant melanoma, rectal adenocarcinoma and unknown primary tumour in one case each. The left arm was involved in seven cases and the right in 11. All patients experienced immediate relief from the pre-operative pain, although three patients complained of a residual discomfort during motion. In these three cases the residual pain can easily be managed with use of oral non-morphinic drugs. The functional aspect was not evaluated in two patients who died in the early post-operative period as a result of their general condition. In 15 patients, the post-operative range of motion was at least 80% of a normal humerus mobility. One patient encountered motion limitation because of an important lymph oedema. There was no infection, one patient had a temporary radial palsy with a complete restoration after a period of 5 days. No migration of the material was observed during an average follow-up of 9 months (range: 1-24).
Hemangiopericytoma is a rare vascular tumor originating from pericytes. The main manifestation is a growing mass. Although computed tomodensitometry and MRI are the best diagnostic procedures, the diagnosis is made only after microscopic examination. The malignancy of this tumor is not well established. In fact, there is a continuum between benign and malignant hemangiopericytoma. The malignancy is estimated by the number of mitoses and the cellularity. Recurrences occur in 60% of cases. The best treatment is surgical excision. The role of radiation therapy and chemotherapy is not well established. The history of a 51-year-old woman treated by internal hemipelvectomy is presented here.
A 19-year-old white man presented with an Ewing sarcoma of the left cubitus. A preoperative chemotherapy was administered according to the T9 Rosen protocol. A wide excision was performed with a 19 cm bone defect, reconstructed in the same operating time by a non vascularized autologous fibular transfer. The postoperative chemotherapy was administered without any major problem. Both surgical and functional evolution are here presented and the osteointegration is evaluated. A discussion of this type of reconstruction is presented evaluating donor site morbidity and possible complications.
Osteosarcoma of the proximal fibula represents about 2% of all osteosarcomas. The complexity of anatomical structures in this region led in the past to low transfemoral amputation in order to achieve local control. Three patients aged 14, 13 and 14 were treated in our institution and surgical margins were free of tumour after a wide en bloc resection. To achieve that, the lateral wall of the tibia and the anterior tibial artery were taken out with the proximal fibula. All three patients are alive without evidence of disease. The functional results are evaluated according to Enneking system recommended and adopted by the Musculo-Skeletal-Tumor Society (M.S.T.S). Overall functional results were 80, 100 and 100%.
Until recently, tumours involving the pelvis were usually treated by hemipelvectomy, otherwise called "hindquarter amputation". A more recent approach of treating these tumours is the 'conservative hemipelvectomy', which consists of removing the tumour and sparing the lower extremity. A patient with Ewing's sarcoma of the pelvis underwent such a procedure. The femoral head was fixed temporarily to the remaining parts of the acetabulum and the iliac wing by a Steinman pin. The Steinman pin was removed 6 weeks after the operation and the patient was then put into traction for another 6 weeks. Weight-bearing was gradually allowed after 3 to 6 months. The patient remodelled a neoacetabulum, which gave sufficient stability to the hip joint. Walking without external help was possible. The patient presented with a 2 cm limb-shortening. No local recurrence was observed during a follow-up of 30 months. This experience with internal hemipelvectomy shows an encouraging result in terms of tumour control and gait function.
791 patients, among them 59 dental technicians and 732 other patients, were tested with the denture material series (DMS) recommended by the German Contact Dermatitis Research Group (DKG) in the hospitals of the Information Network of Departments of Dermatology (IVDK) between January 1990 and July 1993. Most frequently, positive reactions occurred to cadmium chloride in both groups. However, there was no evidence at all for relevance of these reactions. Benzoyl peroxide (BPO) ranked 2nd in patch test positivity. Although not statistically significant, reactions were more frequent in dental technicians, who might be exposed to BPO the in working environment. Methyl methacrylate (MMA) and triethylene glycol dimethacrylate (TEGDMA) were common sensitizers in dental technicians but not in other patients. This finding, too, has its explanation in the working process of manufacturing dental prostheses.
Vascular occlusion between bone cyst and intramedullary venous system seems to be the primum movens in the genesis of a unicameral bone cyst. High speed injection of saline and alternative aspiration injection of the cyst fluid and reaming of the medullary cavity clearly open vascular channels connecting the bone cyst to the intramedullary venous system. This was monitored by pre- and postmanipulative radiographs. This technique was employed in 12 patients with a unicameral bone cyst. All but one went on to healing with increasing diameter of the cortical bone and filling of the cystic cavity.
Three cases of lymphangiosarcoma have been followed recently. All were finally treated by amputation. Only one is actually disease-free. The other two developed local recurrence at the thoracic cage. An extensive review of the literature follows the case presentation.