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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of malignant melanoma of the quadriceps tendon is reported. This is an uncommon soft tissue sarcoma of melanocytic origin. The appearance on MRI depends on its melanin content. The microscopic appearance is distinctive and prognosis is poor. This tumor should be kept in mind when a nodular lesion is detected in specific tendon or aponeurosis.
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PMID:[Malignant melanoma of soft tissues. Apropos of a case]. 975 9

The authors report on their experience of lesionectomies close to or in the thalamus, basal ganglia, third ventricle and in the temporal lobe. The resection itself is performed stereotactically, MRI or CT guided, either microscopically or endoscopically through a sleeve designed by one of the authors and named PAN working sleeve. Over the last four years this new minimally invasive technique has been successfully applied in 39 cases. Eighteen patients with 11 astrocytoma (6AA, 5All), 5 cavernoma and 2 metastases (melanoma, adenocarcinoma) of the basal ganglion-thalamus area and the trigonum were resected by means of a frontal or an occipital burr-hole, whereby in some cases there were subtotal resections. With four of these patients an existing hemiparesis increased by one degree (according to the proposal of the British Medical Research Council I-V). Seventeen patients with lesions in the foramen Monroi and in the third ventricle also underwent operation by means of frontal access, and in each case there was a total resection. Two of the patients required a shunt due to a persistent hydrocephalus internus. In one of these cases there was intraventricular bleeding which necessitated an intra-operative craniotomy. Four patients with intractable epilepsy were operated through a burr-hole in the anterior area of the os zygomaticum. Three patients were submitted to a selective resection of mesial structures and one to an anterior temporal lobe resection. To date the four patients have had no further seizures and no deficits have been observed.
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PMID:Minimally invasive lesionectomies through a stereotactically guided working sleeve. 1004 56

Twenty patients with malignant uveal melanoma were treated at the The Svedbergh cyclotron in Uppsala from 1989 to 1991. Each tumour received a total dose of 54.6 Gy in four equal fractions on four following days. After treatment the melanoma in all eyes showed decrease in size combined with irradiation retinopathy. In eight patients the treatment was successful after five years. Nine eyes had to be enucleated, two due to recurrence and seven due to neovascular glaucoma. Three patients died, two from metastases and one from heart disease. In all patients the visual acuity was dependent on the distance between the irradiation field and the macula or optic nerve. Each patient suffered from transient post irradiation skin erythema and permanent loss of eyelashes and eyebrows when these were included in the irradiation field. The development of secondary glaucoma was positively correlated with tumour volume, but not to the age or sex of the patients. Histological examination of all the enucleated eyes revealed residual viable tumour without obvious radiation damage: mitotic figures were not identified. MRI examination, performed before and after treatment, demonstrated a marked shift in water binding properties after irradiation. The final visual acuity was dependent on the location of the tumour.
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PMID:Proton irradiation of malignant uveal melanoma. A five year follow-up of patients treated in Uppsala, Sweden. 1005 9

Attempts to improve human tumor detection by non-radioactive magnetic resonance techniques have led several investigators to develop antibody-linked paramagnetic contrast agents. Initial studies focused on gadolinium conjugated to monoclonal antibodies. However, very high levels of this contrast agent were needed to significantly reduce proton relaxation times and obtain improved MR images. The use of magnetite (Fe 3O 4) as an MR contrast agent provides a magnetic moment that is approximately one order of magnitude larger than gadolinium. In this study monoclonal antibodies 44 x 14 (specific for squamous cell carcinoma) and 436G10 (specific for melanoma) were obtained from ammonium sulfate precipitation of tumor ascitic fluid. Equal volumes of magnetite solution (1.87 mg Fe/ml) and antibody solution 44 x 14 (5.24 mg protein/ml) and 436G10 (0.64 mg protein/ml) were mixed and sonicated. The 44 x 14-magnetite and 436G10-magnetite solutions were then added to equal volumes of M20 and P3 squamous cell carcinoma cell lines. T1 and T2 values were obtained on a Praxis II NMR spectrometer equipped with a 10 mm probe and 0.25 Tesla permanent magnet. The T2 relaxation times of the magnetite-antibody-cell mixtures were 31 ms with an R = 0.985 for both experimental samples. Our results demonstrate a significant decrease in T2 by binding of the magnetite-coated antibodies to these melanoma and carcinoma cells in vitro. The possibility of detecting subclinical local and metastatic disease with magnetite linked to monoclonal antibodies followed by MRI guided laser tumor ablation therapy may render this technique clinically attractive for treatment of deep-seated tumors.
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PMID:Monoclonal antibody-coated magnetite particles as contrast agents for MR imaging and laser therapy of human tumors. 1014 59

Tumor proliferation may be predictive for malignant progression and response to fractionated therapy of cancer. The purpose of the present work was to investigate whether the proliferation activity of solid tumors can be assessed in vivo from the proton relaxation times, T1 and T2. Tumors of four amelanotic human melanoma xenograft lines were studied. Three parameters were used to represent tumor proliferation activity; the volume doubling time, Tvol, the potential doubling time, Tpot, and the fraction of cells in S-phase. Tvol was determined from volumetric growth data. Tpot and S-phase fraction were determined by flow cytometric analysis of tumor cells after bromodeoxyuridine (BrdU) incorporation in vivo. T1 and T2 were measured by 1H-MRI in vivo, using spin-echo pulse sequences. The proliferation parameters and relaxation times differed considerably among the tumor lines. Significant correlations were found between the proliferation parameters and the relaxation times, regardless of whether Tvol, Tpot, or S-phase fraction was considered. Tumors with short Tvol and Tpot and high S-phase fraction had long T1 and T2 compared to tumors with long Tvol and Tpot and low S-phase fraction. The elongated T1 and T2 of fast growing tumors were probably due to increased interstitial and/or intravascular water content. The present results suggest that in vivo spin-echo 1H-MRI can be used to discriminate between tumors of high and low proliferation activity.
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PMID:Measurement of proliferation activity in human melanoma xenografts by magnetic resonance imaging. 1019 82

A Hurthle cell tumor (oncocytoma) of the thyroid presented as a hypermetabolic focus in a fluorodeoxyglucose positron emission tomography (FDG PET) study which was performed as staging procedure in a patient with malignant melanoma. This finding led to the initial diagnosis of a metastasis. In contrast, multiple liver metastases, seen on MRI and sonography, did not show any increased FDG uptake. Cytology results of one liver mass confirmed a melanoma metastasis, and of the neck mass, a Hurthle cell tumor. The Hurthle cell tumor was, based on clinical evidence, thought to be benign. This is the first description of a FDG PET-positive benign Hurthle cell tumor, with FDG PET-negative liver metastases of a malignant melanoma, in the same patient.
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PMID:FDG PET-negative liver metastases of a malignant melanoma and FDG PET-positive hurthle cell tumor of the thyroid. 1037 3

The prognosis of malignant disease is essentially determined by the metastatic potential of the primary tumor. In the past, scientific attention was chiefly directed to systemic metastasis. A multitude of biological and molecular tumor markers and mechanisms has been uncovered enabling a better contemporary understanding of the process of hematogenic metastasis. This is in contrast with our knowledge of the mechanisms and pathways of lymphatic tumor spread, which is rather limited. We do know, however, that adequate surgical clearance of the regional lymphatics improves treatment results of many tumors. How far this lymph node dissection is directly therapeutic is a source of controversy. While in some instances, a stage-adjusted survival benefit was demonstrated, this may very well be attributable at least in part to the phenomenon of stage migration (Will Rodgers phenomenon) through better staging. However, it is uncontested that an established diagnosis of regional lymphatic spread is prognostically significant and should influence the indication for additional therapy and eventually for an intensive follow-up. For many tumors, the indication for adjuvant chemotherapy depends on the nodal status. On the other hand, it is equally well known that aggressive lymphatic dissection increases perioperative morbidity and even mortality. Long-term sequellae from regional lymphatic dissection are common and the effect on the local, maybe even the systemic immunological response to the malignant disease, remains unclear. To incur such risk seems especially problematic in those patients without any lymphatic spread at the time of the pathologist's work-up. Thus, there is ongoing debate about the rationale, value, extent, advantage, or disadvantage of regional surgical lymph node dissection or even radiotherapy of the regional lymphatic drainage area for many different tumors. A considerable step forward could be made if there was any diagnostic modality enabling a reliable preoperative lymph node staging. However, there is none. General criteria like size, shape, structure, or texture in variable imaging modalities are unreliable. While it is still too early to definitely evaluate in this context new diagnostic modalities like PET, immunoscintigraphy, or contrast-enhanced MRI, the initial results do not provoke clear enthusiasm toward the development of a sensitive and specific staging tool with regard to the nodal status. Adequate specificity may be obtained by external or endoluminal ultrasound-guided fine needle biopsies. However, uncertainty arises from eventually unrepresentative tissue sampling. The sentinel lymphonodectomy technique may remedy the dilemma, enabling a risk-adapted, individual indication for regional lymphatic dissection. This concept, first introduced in 1977 by Cabanas into the treatment of penis carcinoma, is based on the evidence of orderly and predictable lymphatic drainage pathways. Tumor cell progression within the lymphatic system seems to follow a sequential pattern. Primary draining lymph nodes possess the structural and functional capability to retain and to fight tumor cells efficiently. The 'sentinel node' is defined as the first tumor draining filter, and, if uninvolved, should thus adequately predict the nodal status of the disease. Skip metastases beyond an uninvolved sentinel node are supposed to be a very rare event. The reliability of the 'Cabanas approach', however, was limited by its relatively poor localization technique, and therefore failed to gain widespread acceptance. Unfortunately, the significance of the concept was not fully appreciated at the time. It is to Morton's credit that the procedure was reinstituted in malignant melanoma through a dye injection technique at the primary tumor site. This led to a rapid development and refinement of intraoperative lymphatic mapping. One major step in this process was to use radiolabeled colloids in conjunction with gamma-camera imaging or gamma probe-guided detection of the sentinel node. At present, a multitude of studies are conducted in a variety of tumors and sites, aiming at further refinements of the technique or at clinical evaluation in comparison with established lympadenectomy. The results may well change many aspects of our operative strategy in the near future. However, assuming a technically optimized procedure, will this solve the underlying tumor biological and clinical problem with respect to the necessity and efficacy of a regional lymph node dissection in node-positive cases? This is not the case; moreover, there are additional questions raised and left unanswered so far. Without any doubt, the rate of unnecessary diagnostic lymph node dissections can be considerably reduced as soon as the sentinel node concept is sufficiently validated for general use outside clinical trials. This would be a clear step forward. It is undetermined, however, how far a cancer patient with a positive sentinel node-thus already proven lymphatic metastases-would still profit from a more or less extensive lymph node dissection. It might be sufficient to use the staging information obtained through the sentinel node's status alone to decide upon adjuvant therapies. A further aspect arises from the possibility for investigating this single and supposedly most representative lymph node in far more detail than it would be possible for the large number of nodes previously sampled in conventional lymphatic dissections. This more extensive work-up may include serial sectioning, immunological and molecular techniques to enhance the sensitivity for micrometastases detection. However, very little is known about the true prognostic significance of such conventionally occult micrometastases, and even less experience exists as to the value of adjuvant therapies in those cases. Thus, while the sentinel node procedure will probably enable a more precise though less invasive lymphatic staging of malignant disease, it raises a number of important questions, as well. The general principles of multimodal treatment will have to be redefined with regard to the new diagnostic tool, which will require extensive prospective and randomized testing before a safe and reliable advantage for the patients may be established.
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PMID:The 'Sentinel Node' Concept: More Questions Raised than Answers Provided? 1038 28

Stereotactic radiosurgery (SR) is being used with increasing frequency in the treatment of brain metastases. This study provides data from a clinical experience with radiosurgery in the treatment of cases with multiple metastases and identifies parameters that may be useful in the proper selection and therapy of these patients. From January 1993 to April 1997, 97 patients (43 women and 54 men; median age 58 years) suffering from multiple brain metastases (median 3; range 2-4) in MRI scans, received SR with the Gamma Knife. The median dose at the tumor margin was 20 Gy (range 17-30 Gy). Median tumor volume was 3900 cmm (range 100-10,000). Different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness and ataxia had been the predominant neurological symptoms. Major histologies included lung carcinoma (44%), breast cancer (21%), renal cell carcinoma (10%), colorectal cancer (8%), and melanoma (7%). The median survival time was 6 months after SR. The actual one-year survival rate was 26%. In univariate and multivariate analysis, a higher Karnofsky performance rating and absence of extracranial metastases had a significantly positive effect on survival. Local tumor control was achieved in 94% of the patients. Complications included the onset of peritumoral edema (n = 5) and necrosis (n = 1). SR induces a significant tumor remission accompanied by neurological improvement and, therefore, provides the opportunity for prolonged high quality survival. We conclude that radiosurgical treatment of multiple brain metastases leads to an equivalent rate of survival when compared to the historic experience of patients treated with whole brain radiotherapy. Patients presenting initially with a higher Karnofsky performance rating and without extracranial metastases had a median survival time of nine months. Each such case should therefore be evaluated based on these factors to determine an optimal treatment regimen.
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PMID:Prognostic factor analysis for multiple brain metastases after gamma knife radiosurgery: results in 97 patients. 1042 Oct 75

PET and SPECT are molecular imaging techniques that use radiolabeled molecules to image molecular interactions of biological processes in vivo. PET imaging technologies have been developed to provide a pathway to the patient from the experimental paradigms of biological and pharmaceutical sciences in genetically engineered and tissue transplanted mouse models of disease. PET provides a novel way for molecular therapies and molecular diagnostics to come together in the discovery of molecules that can be used in low mass amounts to image the function of a target and, by elevating the mass, to pharmacologically modify the function of the target. In both cases, the molecules are the same or analogs of each other. PET can be used to titrate drugs to their sites of action within organ systems in vivo and to assay biological outcomes of the processes being modified in the mouse and the patient. The goal is to provide a novel way to improve the rates of discovery and approval of radiopharmaceuticals and pharmaceuticals. Extending this relationship into clinical practice can improve drug use by providing molecular diagnostics in concert with molecular therapeutics. Diseases are biological processes, and molecular imaging with PET is sensitive and informative to these processes. This sensitivity is exemplified by the detection of disease with PET without evidence of anatomic changes on CT and MRI. These biological changes are seen early in the course of disease, even in asymptomatic stages, as illustrated by the metabolic abnormalities detected with PET and FDG in Huntington's and familial Alzheimer's diseases 7 and 5 y, respectively, before symptoms appear. Differentiation of viable from nonviable tissue is fundamentally a metabolic question, as shown by the use of PET to differentiate patients with coronary artery disease who will benefit from revascularization from those who will not. Although beginning within a specific organ, cancer is a systemic disease the most devastating consequences of which result from metastases. Whole-body PET imaging with FDG enables inspection of glucose metabolism in all organ systems in a single examination to improve the detection and staging of cancer, selection of therapy, and assessment of therapeutic response. In lung and colorectal cancers, melanoma, and lymphoma, PET FDG improves the accuracy of detection and staging from 8% to 43% over conventional work-ups and results in treatment changes in 20%-40% of the patients, depending on the clinical question. Approximately 65% are upstaged because unsuspected metastases are detected, and 35% are downstaged because a structural diagnosis of lesions is changed from malignant to benign. Similar results are now being shown for other cancers. The main difference between CT, sonography, MRI, and PET or SPECT is not technologic but, rather, a difference between detecting and characterizing a disease by its anatomic features as opposed to its biology. The importance and success of developing new molecular imaging probes is increasing as PET becomes integral to the study of the integrative mammalian biology of disease and as molecular therapies targeting the biological processes of disease are developed.
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PMID:PET: the merging of biology and imaging into molecular imaging. 1076 68

Diseases are biological processes, and molecular imaging with positron emission tomography (PET) is sensitive to and informative of these processes. This is illustrated by detection of biological abnormalities in neurological disorders with no computed tomography or MRI anatomic changes, as well as even before symptoms are expressed. PET whole body imaging in cancer provides the means to (i) identify early disease, (ii) differentiate benign from malignant lesions, (iii) examine all organs for metastases, and (iv) determine therapeutic effectiveness. Diagnostic accuracy of PET is 8-43% higher than conventional procedures and changes treatment in 20-40% of the patients, depending on the clinical question, in lung and colorectal cancers, melanoma, and lymphoma, with similar findings in breast, ovarian, head and neck, and renal cancers. A microPET scanner for mice, in concert with human PET systems, provides a novel technology for molecular imaging assays of metabolism and signal transduction to gene expression, from mice to patients: e.g., PET reporter gene assays are used to trace the location and temporal level of expression of therapeutic and endogenous genes. PET probes and drugs are being developed together-in low mass amounts, as molecular imaging probes to image the function of targets without disturbing them, and in mass amounts to modify the target's function as a drug. Molecular imaging by PET, optical technologies, magnetic resonance imaging, single photon emission tomography, and other technologies are assisting in moving research findings from in vitro biology to in vivo integrative mammalian biology of disease.
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PMID:Positron emission tomography provides molecular imaging of biological processes. 1092 74


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