1/12. Spinal malignant melanotic schwannoma. Case report.The authors report a rare case of spinal cord compression syndrome due to a malignant melanotic schwannoma. Pathogenesis, diagnostic difficulty and therapeutical problems are discussed. The authors conclude that such tumours should be surgically treated due to the possibility of a benign clinical behaviour even in those cases showing malignant histological features.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/12. Chondromyxoid fibroma of two thoracic vertebrae.We report on a case of chondromyxoid fibroma involving two adjacent thoracic vertebrae with features of aggressive behaviour on radiographs, CT and MRI. histology revealed typical chondromyxoid fibroma with unusually coarse calcifications. Chondromyxoid fibroma of the spine is rare, and only 30 of these tumours have been reported so far. Involvement of two contiguous vertebral bodies by chondromyxoid fibroma, as reported here, appears exceptional.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
3/12. Fibromatosis.Fibromatosis represents a diverse group of fibroproliferative tumours. Their behaviour and pathological qualities are situated in an intermediate position between benign and malignant disease. The following represents the pathological and radiological presentation of a 29-year-old female with fibromatosis.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
4/12. Spinal melanotic schwannoma: a tumour with poor prognosis.AIM: To clarify the prognosis of melanotic schwannoma. This is a rare tumour which is generally considered as a benign lesion, reported in many cases with a short follow-up only. methods AND RESULTS: Five cases of spinal melanotic schwannoma were retrospectively studied. The tumours were examined using standard histological, immunohistochemical and ultrastructural methods. No features of malignancy (high mitotic count, atypia or necrosis) were found in the primary tumours. The follow-up period ranged from 3 to 7 years. Malignant clinical behaviour was clear-cut in four cases: three patients died from metastases to various sites and one presented several discrete spinal tumours of the same type seven years after the first operation. Only one patient presented no recurrence and was free of disease 6 years after initial diagnosis. The review of 57 cases of the literature (including our cases), showed that 15% of the cases had recurrences and 26.3% were complicated by metastasis. Only 53% of the cases followed for more than 5 years, were free of disease vs. 67.5% of the cases with shorter follow-up. Twenty additional cases had no follow-up. CONCLUSION: Appropriate long-term follow-up is required for all melanotic schwannomas, as it may recur or metastasize after more than 5 years, even in the absence of overt malignant histological features.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
5/12. Metastasising clear cell odontogenic carcinoma: a case report and review of the literature.Primary odontogenic carcinomas are rare and examples which have metastasised are even more uncommon. We describe the first reported case of a clear cell odontogenic carcinoma which metastasised to distant bones, namely the 5th lumbar vertebra and hip, 3 years after initial diagnosis. The initial incisional biopsy was thought to represent a calcifying epithelial odontogenic tumour, but in the subsequent resection the tumour showed a prominent clear cell component admixed with squamous cells showing peripheral palisading, widespread infiltration and necrosis indicating a malignant neoplasm. Radiologically guided biopsy revealed a metastatic lesion in L5 vertebrae and left hip, confirmed by immunohistochemistry. The metastatic lesion had similar appearances to the first biopsy, and diagnosis was confirmed by comparison of histological features, immunohistochemistry and exclusion of a second primary lesion by clinical examination and imaging. The diagnosis of clear cell odontogenic carcinoma is a difficult one to make. The behaviour of these tumours is unpredictable. This case confirms that clear cell odontogenic carcinomas have the potential for distant metastasis and require long-term follow up.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
6/12. Absence of multiple local minima effects in intensity modulated optimization with dose-volume constraints.This paper reports on the analysis of intensity modulated radiation treatment optimization problems in the presence of non-convex feasible parameter spaces caused by the specification of dose-volume constraints for the organs-at-risk (OARs). The main aim was to determine whether the presence of those non-convex spaces affects the optimization of clinical cases in any significant way. This was done in two phases: (1) Using a carefully designed two-dimensional mathematical phantom that exhibits two controllable minima and with randomly initialized beamlet weights, we developed a methodology for exploring the nature of the convergence characteristics of quadratic cost function optimizations (deterministic or stochastic). The methodology is based on observing the statistical behaviour of the residual cost at the end of optimizations in which the stopping criterion is progressively more demanding and carrying out those optimizations to very small error changes per iteration. (2) Seven clinical cases were then analysed with dose-volume constraints that are stronger than originally used in the clinic. The clinical cases are two prostate cases differently posed, a meningioma case, two head-and-neck cases, a spleen case and a spine case. Of the 14 different sets of optimizations (with and without the specification of maximum doses allowed for the OARs), 12 fail to show any effect due to the existence of non-convex feasible spaces. The remaining two sets of optimizations show evidence of multiple minima in the solutions, but those minima are very close to each other in cost and the resulting treatment plans are practically identical, as measured by the quality of the dose-volume histograms (DVHs). We discuss the differences between fluence maps resulting from those similar treatment plans. We provide a possible reason for the observed results and conclude that, although the study is necessarily limited, the annealing characteristics of a simulated annealing method may not be justified in clinical optimization in the presence of dose-volume constraints. The results of optimizations by the Newton gradient (NG) method with a quadratic cost function are reported in detail. An adaptive simulated annealing method, optimizing the same function, and the dynamically penalized likelihood method, optimizing a log likelihood function, have also been used in the study. The results of the latter two methods have only been discussed briefly, as they yielded the same conclusions as the NG method.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
7/12. Primary sclerosing epithelioid fibrosarcoma of the sacrum: a case report and review of the literature.Sclerosing epithelioid fibrosarcoma is a rare tumour characterised histologically by a predominant population of epithelioid cells arranged in strands and nests, embedded in a fibrotic and hyalinised stroma. It is a low grade tumour with an indolent course. A 48 year old woman presented with a painful swelling over her back for six months. Investigation and biopsy revealed features of sclerosing epithelioid fibrosarcoma involving the left half of the sacrum, left sacro-iliac joint, and posterior part of the left ilium. Preoperative radiotherapy and wide location excision of the tumour were followed by metastatic recurrence of the tumour in the lung and scalp six years after initial presentation. The tumour showed typical histology of sclerosing epithelioid fibrosarcoma. The radiological features confirmed its primary location in the sacrum. The patient declined chemotherapy and died of disseminated disease eight years after initial presentation. review of the literature confirms the fact that sclerosing epithelioid fibrosarcoma, despite its low grade, is a clinicopathologically distinct tumour with full malignant potential, the recurrence, metastasis, and mortality rate being 48%, 60%, and 35%, respectively. Sclerosing epithelioid fibrosarcoma can occur as a primary bone tumour, the clinical behaviour of which is probably similar to its soft tissue counterpart.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
8/12. Chondroid lipoma of the trunk: MRI appearance and pathologic correlation.Chondroid lipoma is a rare tumour of adipose tissue, bearing a strikingly close pathologic resemblance to myxoid liposarcoma and extraskeletal myxoid chondrosarcoma. Unlike these malignant tumours, chondroid lipoma has a non-aggressive behaviour and does not require radical treatment. Although repeatedly reported in the proximal extremities and limb girdles, this rare entity may less frequently be observed in the trunk. We describe the imaging findings of a chondroid lipoma in the trunk and provide a discussion on the radiologic-pathologic correlation and differential diagnosis.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
9/12. Extraspinal ependymoma in the sacrococcygeal region. A case report with ultrastructural, immunohistochemical and cytophotometric studies.We describe on a primary, subcutaneous sacrococcygeal ependymoma presenting in a young female patient. Detailed immunohistochemical and electron microscopic examinations were performed. Out of the 40 similar cases reported in literature this is the first in which the determination of dna content was also used to predict biological behaviour. The tumour proved to be aneuploid with low proliferative capacity in spite of absent histological signs of malignancy. It is suggested that dna determination may be helpful in establishing prognosis and that it may contribute to a better understanding of the biological behaviour of this tumour.- - - - - - - - - - ranking = 2keywords = behaviour (Clic here for more details about this article) |
10/12. Sacrococcigeal and vertebral chordomas. Report of three cases and review of the literature.Three cases of sacrococcygeal and vertebral chordoma are described. Histogenetic and anatomopathological aspects with particular reference to differential diagnosis from similarly distributed neoplasias are discussed. Anti-cytoskeleton monoclonal antibodies were used to this purpose. The clinical profile of sacrococcygeal and vertebral chordomas is characterized by a pronounced metastatic potential; radiation treatment can only partially counter their biological behaviour, while chemotherapy has proved little or no effectiveness. Where possible, radical surgery is currently the only treatment to guarantee long-term survival or complete cure. Palliative surgery, associate with efficient painkilling, offers a better quality of life and slows down the progress of the disease.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
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