1/9. Use of short implants for functional restoration of the mandible after giant cell tumor removal. Case report.The giant cell tumor of the jaws is a rare benign lesion, it has a slow and progressive evolution and it is locally aggressive. Its etiopathogenesis is unknown, it is most common in the mandible and it is often asymptomatic but pain arises from palpation of the area. diagnosis is made by radiological and histological examination and surgical treatment is necessary. The clinical case of a 28-year-old man affected by a giant cell tumor of the mandible with an aggressive clinical and radiographical behaviour is reported. The patient showed a jaw swelling covered by hyperemic fibro-mucous tissue from tooth 4.6 to 3.4, absence of cortical bone and mobility of teeth. He also reported lip anesthesia. The giant cell tumor diagnosis was made with orthopantomography (OPT), computed tomography (CT) and needle biopsy. The lesion was surgically removed and histological examination confirmed the diagnosis. In spite of the wide loss of bony substance after surgery, the patient was provided with an implant supported fixed prosthesis without previous bone graft. In this case short implants allowed the prosthetic rehabilitation of a mandible with severe ''resorption'' due to surgical removal of a tumor. Implants were placed in the residual bone volume and successfully used to support a fixed prosthesis. The final result is optimal as is the quality of life of the young patient.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
2/9. Acute destruction of the hip joints and rapid resorption of femoral head in patients with rheumatoid arthritis.We report three rheumatoid arthritis (RA) cases with acute destruction of hip joint and rapid resorption of femoral head. The condition occurred in less than 6 months and closely resembled rapid destructive coxarthrosis. All three patients were postmenopausal women with active RA who had been taking steroids. Two of the patients were taking prednisolone (PSL) of over 20 mg as maximum dose per day, and all patients were resistant to disease-modifying anti-rheumatic drugs (DMARDs). Other than the problems of their hip joints, one had a giant bursitis around the pathological side of the hip joint, another had multiple rheumatoid nodules and skin infarction, and the other suffered from insufficiency fracture of the contralateral femoral subcapital lesion. As a result, all of them had total hip arthroplasty. We recommend taking repetitive radiographs for RA patients with continuing severe hip pain.- - - - - - - - - - ranking = 0.14285714285714keywords = giant (Clic here for more details about this article) |
3/9. in vitro bone resorption by isolated multinucleated giant cells from giant cell tumour of bone: light and electron microscopic study.The behaviour of multinucleated giant cells (GCs), obtained from a giant cell tumour of the tibia and cultured on glass coverslips or on devitalized bone slices, was studied using light and electron microscopy. Monitoring the GCs on bone slices by phase-contrast microscopy revealed that they had removed calcified bone matrix resulting in excavation of lacunae, with subsequent lateral extension and perforation of the bone slices. Electron microscopy demonstrated for the first time that the GCs responsible for exavating lacunae had two specific membrane modifications, ruffled border and clear zone, and showed basically similar cytoplasmic fine structures to those of osteoclasts. fluorescence images of the GCs on glass and on bone after rhodamine-conjugated phalloidin staining revealed that most of the GCs had an intensely fluorescent peripheral band composed of a number of F-actin dots called podosomes. Some GCs showed unusual arrangements of podosomes suggesting abortive attempts at GC formation. We have demonstrated that the band structure of the GCs cultured on bone is intimately involved in bone resorption. Two stromal cell types could be recognized. The predominant type, which seemed to be the only neoplastic element because of its proliferative capability, showed quite different fine structural and cytoskeletal features from the GCs. The other type, which was much less frequent and seemed not to proliferate, had morphological similarities to the GCs, and seemed to be their precursor. Importantly GCs cultured on bone and the osteoclasts share common structures for adhesion to and resorption of bone, strongly supporting the view that the GCs of the giant cell tumour of bone are potentially active bone resorbers and can be regarded as osteoclasts.- - - - - - - - - - ranking = 1.5714285714286keywords = giant (Clic here for more details about this article) |
4/9. A small aneurysmal bone cyst restricted to the cortical bone of the femur resembling so-called subperiosteal giant cell tumor or subperiosteal osteoclasia.We report a 16-year-old Japanese girl with a cystic lesion restricted to the cortical bone under the periosteum of the diaphysis of the left femur. Roentgenograms showed a long, oval translucent lesion in frontal view and an eccentric erosive lesion in lateral view. Computed tomography showed a distinct intracortical lesion. The lesion, which was excised en bloc, measured 3 x 2 x 2 cm. The outer layer of the cortical bone was eroded eccentrically. From the margin of the eroded bone, thin fragile bony tissue and preserved periosteum extended like the roof of a dome. Multicystic structures, filled with blood, were lined with fibrous granulation and occasional giant cells. Histologically, this lesion falls within the category of aneurysmal bone cyst. However this case is of a rare type, since the lesion was relatively small, and showed a very specific intracortical location, in marked contrast to typical aneurysmal bone cyst. Additionally, this lesion is similar to so-called subperiosteal giant cell tumor or subperiosteal osteoclasia described in the literature.- - - - - - - - - - ranking = 0.85714285714286keywords = giant (Clic here for more details about this article) |
5/9. Localized osteolysis in stable, non-septic total hip replacement.We are reporting four cases of extensive, localized bone resorption adjacent to a rigidly anchored, cemented total hip replacement. None of these hips showed evidence of infection on clinical, bacteriological, or pathological evaluation. The tissue from the regions of osteolysis showed sheets of macrophages and foreign-body giant cells invading the femoral cortices. Abundant methylmethacrylate particulate debris was present in the tissues, but polyethylene wear debris was absent. The histological appearance of this tissue resembled that reported about loosened total hip implants with the exception of the synovial-like layer at the cement surface. The cases reported here show that aggressive bone lysis may occur around stable cemented total hip arthroplasties without the presence of sepsis or malignant disease.- - - - - - - - - - ranking = 0.14285714285714keywords = giant (Clic here for more details about this article) |
6/9. Calcium-oxalate-crystal-induced bone disease.A 13-year-old boy with primary hyperoxaluria and a successful renal allograft developed symptomatic bone disease, hypercalcemia, and hypercalciuria. Transiliac bone biopsy revealed calcium oxalate crystals in the marrow within mononuclear phagocytes and multinucleated giant cells. Deep resorption bays were seen adjacent to these crystal-cell aggregates. serum 1,25-(OH)2-vitamin d (calcitriol) and iPTH concentrations were low or normal. We suggest that hypercalcemia results from macrophage-mediated bone resorption initiated by Ca oxalate crystal deposition.- - - - - - - - - - ranking = 0.14285714285714keywords = giant (Clic here for more details about this article) |
7/9. Characterization of a subtype of primary osteoclastoma: extracellular calcium but not calcitonin inhibits aggressive HLA-DR-positive osteoclastoma possessing 'functional' calcitonin receptors.We report here a case of primary osteoclastoma that despite possessing HLA-DR-positive status and 'functional' calcitonin receptors, exhibited aggressive in vitro and in vivo bone resorptive activity. In the osteoclast bone slice assay employing scanning electron microscopy, the giant cell-mediated bone resorption was uninhibited by salmon calcitonin (10 nM) and significantly inhibited by raised extracellular calcium (20 mM). In Fura-2AM based microspectrofluorimetric assays, the presence of the 'functional' calcitonin receptors was ascertained by a rise in intracellular calcium induced by calcitonin and high extracellular calcium. These findings provide evidence for a hitherto unrecognized subtype of giant cells that have HLA-DR-positive status, exhibit avid bone resorptive activity, but remain insensitive to calcitonin despite possessing calcitonin receptors.- - - - - - - - - - ranking = 0.28571428571429keywords = giant (Clic here for more details about this article) |
8/9. Characterization of a cell line derived from a human giant cell tumor that stimulates osteoclastic bone resorption.giant cell tumors of bone are common but unusual tumors that are comprised of multiple cell types. Most attention has been focused on the giant cells, which resemble osteoclasts morphologically and functionally. This study examines the properties of a cell line derived from mononuclear cells from one of these tumors, since it appears likely that these cells may be able to influence the activities of cells with the osteoclast phenotype. This cell line, C433, has the following characteristics: (1) it represents undifferentiated cells, not recognized by any known antigenic markers for leukocytes; (2) it contains tartrate-resistant acid phosphatase; (3) it responds to the osteotropic factors 1,25 dihydroxyvitamin D3, insulin-like growth factor i and II, but not to parathyroid hormone; (4) it forms sarcomas in nude mice; and (5) it produces an activity that stimulates isolated avian and rat osteoclasts to resorb bone. This cell line may be useful in examining interactions between osteoclasts and accessory cells involved in bone resorption.- - - - - - - - - - ranking = 0.71428571428571keywords = giant (Clic here for more details about this article) |
9/9. Extensive localized bone resorption in the femur following total hip replacement.Extensive localized bone resorption within the femur was observed after four total hip replacements. The amount and location of the resorption suggested the presence of infection or tumor, but there was no evidence of either condition and the roentgenographic appearance differed from that associated with a loose uncemented endoprosthesis or a grossly loose femoral component of a total hip replacement. At reoperation the femoral components were not rigidly fixed but were only slightly loose. Histologically there were sheets of macrophages, a few giant cells, and multiple small fragments of a birefringent material, but no inflammatory cells. While the exact mechanism of this serious complication is unclear, the findings suggest that a benign, non-inflammatory, adverse tissue response can occur in relation to the femoral components of total hip replacements that are not rigidly fixed. In all four hips, reimplantation of a new total hip replacement was successful after follow-up of thirteen to eighteen months.- - - - - - - - - - ranking = 0.14285714285714keywords = giant (Clic here for more details about this article) |