Prosthetic reconstruction for tumours of the distal tibia and fibula. (1/136)

We have carried out prosthetic reconstruction in six patients with malignant or aggressively benign bone tumours of the distal tibia or fibula. The diagnoses were osteosarcoma in four patients, parosteal osteosarcoma in one and recurrent giant-cell tumour in one. Five tumours were in the distal tibia and one in the distal fibula. The mean duration of follow-up was 5.3 years (2.0 to 7.1). Reconstruction was achieved using custom-made, hinged prostheses which replaced the distal tibia and the ankle. The mean range of ankle movement after operation was 31 degrees and the joints were stable. The average functional score according to the system of the International Society of Limb Salvage was 24.2 and five of the patients had a good outcome. Complications occurred in two with wound infection and talar collapse. All patients were free from neoplastic disease at the latest follow-up. Prosthetic reconstruction may be used for the treatment of malignant tumours of the distal tibia and fibula in selected patients.  (+info)

Radioimmunoassay for human calcitonin employing synthetic calcitonin M: its clinical application. (2/136)

A sensitive and reliable radioimmunoassay for human calcitonin was described and applied to preliminary clinical studies. 125I-labelled synthetic human calcitonin M was purified by gel filtration with Sephadex G-25 and G-100. A nonequilibrium incubation system was applied at the final volume of incubation mixture of 500 mul, in which pooled plasma from normal subjects or hormone free serum was used as carrier protein at 20% incubation mixture. Dextran T 40 coated charcoal, resuspended in 1% bovine serum albumin buffer, was used for the separation of free from bound tracer. This showed the least nonspecific adsorption of tracer to charcoal. The assay was sensitive to 0.1 ng per milliliter of plasma. Recovery of synthetic human calcitonin added to plasma was found to be 101% (S. D., +/- 8). Diluted plasma from a patient with medullary thyroid carcinoma showed a dilution curve parallel to standards. Basal calcitonin levels were less than 0.3 ng/ml in normal subjects. Relatively high values were found in patients with chronic renal failure and in patients with malignant tumors. Extremely elevated values were found in patients with medullary thyroid carcinoma. Provocative calcium infusion tests were also performed.  (+info)

Tenosynovial giant cell tumor of finger, localized type: a case report. (3/136)

The authors report a typical case of tenosynovial giant cell tumor of the right middle finger of a 31-year-old man. Histologically, this tumor is characterized by a discrete proliferation of rounded synovial-like cells accompanied by a variable number of multinucleated giant cells, inflammatory cells, and xanthoma cells. Clinicopathologically, this tumor is a benign lesion that nonetheless possesses a capacity for local recurrence. Local excision with a small cuff of normal tissue is the treatment of choice in this tumor.  (+info)

In vitro induction of giant cell tumors from cultured hamster islets treated with N-Nitrosobis(2-Oxopropyl)amine. (4/136)

Giant cell carcinoma of the pancreas is a rare tumor. Its histogenesis is still controversial. In a Syrian hamster pancreatic cancer model, tumors similar to human giant cell carcinomas have been induced at an extremely low rate of incidence and after the use of high doses of pancreatic carcinogens. Thus far no tumors of giant cell type have been induced by the in vitro treatment of hamster pancreatic ductal cells with the potent pancreatic carcinogen N-nitrosobis(2-oxopropyl)amine (BOP). In the present study we report the induction of giant cell carcinoma from hamster islets treated with BOP in vitro. The results suggest that in hamsters some component of islet cells, probably stem cells, are the origin of giant cell carcinoma.  (+info)

Localized pigmented villonodular synovitis of the knee joint: neoplasm or reactive granuloma? A review of 18 cases. (5/136)

OBJECTIVE: The localized form of pigmented villonodular synovitis of the knee joint is a rare disease with limited alteration of the synovial membrane, the pathogenesis of which is the subject of controversial discussion. METHODS: Eighteen cases have been documented in our hospital since 1976. All of the patients had additional cartilage or meniscus damage. Treatment consisted of excision of the lesion and the adjacent synovial membrane, as well as therapy of the additional damage. RESULTS: The patients who had received such therapy were followed for 3-9 yr, without any clinical, sonographic or magnetic resonance tomographic signs of recurrence. In addition to the lack of a tendency towards recurrence, none of the cases displayed any further characteristics of the diffuse form of villonodular synovitis, such as invasiveness or malignant transformation. CONCLUSIONS: We therefore suggest that pigmented villonodular synovitis of the knee joint should be classified more strictly than before into a potentially neoplastic (diffuse) form and a reactive granulomatous (local) form. From the cases observed, we conclude that degenerative joint lesions may be the cause of the reactive granulomatous form.  (+info)

h-Caldesmon as a specific marker for smooth muscle tumors. Comparison with other smooth muscle markers in bone tumors. (6/136)

Caldesmon is a protein widely distributed in smooth and non-smooth muscle cells and is thought to regulate cellular contraction. Its isoform, high-molecular-weight caldesmon (h-CD), was demonstrated to be specific for smooth muscle cells and smooth muscle tumors of the soft tissue and to never be expressed in myofibroblasts. We performed an immunohistochemical study to examine h-CD expression in the following bone tumors: conventional and non-conventional osteosarcoma, 13; malignant fibrous histiocytoma of bone, 5; giant cell tumors of bone, 5; chondroblastoma, 3; metastatic leiomyosarcoma, 2; and rhabdomyosarcoma, 1. Frequent immunoreactivity for muscle actin (alpha-smooth muscle actin or muscle-specific actin) was seen in 11 of 13 osteosarcomas and all other tumors, whereas h-CD was expressed intensely only in 2 leiomyosarcomas. h-CD is considered a specific and useful marker to distinguish smooth muscle tumor from bone tumors with myoid differentiation.  (+info)

Giant-cell tumour of the tendon sheath. Is radiotherapy indicated to prevent recurrence after surgery? (7/136)

Giant-cell tumour of the tendon sheath, also called pigmented villonodular synovitis, is a benign tumour with a high incidence of recurrence. We have tried to identify risk factors for recurrence. Of the 48 patients included in the study, 14 received radiotherapy after surgery. Only two (4%) had a recurrence. This compares favourably with previously reported incidences of between 25% and 45%.  (+info)

Apoptosis in giant cell tumors of bone. (8/136)

Although giant cell tumor of bone (GCT) is characterized by the extensive multinucleated giant cells among mononuclear stromal cells, proliferation of these cells and multinucleation are not without limit in certain cases. Few studies on oncogenesis of GCT have focused on the negative growth control, including growth arrest and apoptosis. The purpose of this study was to investigate the mechanism of cell death in multinucleated giant cells and stromal cells of GCT. In this study, we have demonstrated that GCT cells can undergo apoptosis. The cells in surgical specimen were positively stained in situ nick end labeling methods, and electron micrographs showed the morphological changes associated with apoptosis in some of stromal cells and multinucleated giant cells. A candidate responsible for this apoptosis was then examined using cultured GCT cells. We focused on Fas that is a major trigger of apoptosis. Cultured GCT cells expressed detectable amount of Fas on their surface. Although GCT cells did a little undergo apoptosis following treatment with anti-Fas alone, combination treatment with cyclohexamide led to an increase in apoptosis of the GCT cells. These data suggested that the sensitizing activity of cyclohexamide on anti-Fas mediated cytotoxicity could happen in vitro.  (+info)