989 resultados para SARCOMA MALIGNANT PECOMA


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Galectin-3 is a glycan-binding protein that mediates cell-cell and/or cell-extracellular matrix (ECM) interactions. Although galectin-3 is implicated in the progression of various types of cancers, the mechanisms by which galectin-3 enhances metastasis remain unclear. In order to elucidate the role of galectin-3 in the complex multistage process of cancer metastasis, we examined galectin-3 and galectin-3-binding site expression in a series of 82 spontaneous canine mammary tumors (CMT) and two CMT cell lines. Benign CMT tumors exhibited strong nuclear/cytoplasmic galectin-3 immunostaining, whereas malignant CMT tumors and metastases exhibited dramatically decreased galectin-3 expression with the majority of the immunostaining confined to the cytoplasm. Interestingly, intravascular tumor cells overexpressed galectin-3 regardless of their location. CMT-U27 xenografts displayed the same pattern of galectin-3 expression found in spontaneous malignant CMT. In parallel with the downregulation of galectin-3, malignant CMT displayed an overall loss of galectin-3-binding sites in the ECM and focal expression of galectin-3-binding sites mainly detected in intravascular tumor cells and endothelium. Furthermore, loss of galectin-3-binding sites was correlated with the downregulation of GLT25D1, a beta (1-O) galactosyltransferase that modifies collagen, and upregulation of stromal galectin-1. Finally, GLT25D1 mRNA expression was strikingly downregulated in malignant CMT-U27 compared with the benign cell line, and its expression was further de-creased in a galectin-3 knockdown CMT-U27 cell line. We therefore hypothesized that the loss of galectin-3-binding sites in the ECM in conjunction with the overexpression of galectin-3 in specific tumor cell subpopulations are crucial events for the development of mammary tumor metastases.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Collision tumors consist of two independent but coexisting tumors. This uncommon situation might be easily mistaken for a composite tumor where one histogenetic event originates from two apparently distinct neoplasms. Colorectal collisions are particularly unusual; here, we report the exceedingly rare case of a 61-year-old man with malignant melanoma and adenocarcinoma colliding in the rectum. Collision tumors have an idiopathic pathophysiology and in fact ""accidental meeting"" is accepted by many authors. This article discusses the concepts about cancer development, which are overlooked by this hypothesis, another theory to explain that this rare occurrence involves microenvironment changes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background/Aims: Acinar cell carcinomas are uncommon malignant tumors of the pancreas, accounting for 1-2% of all the cases of exocrine pancreatic tumor. Some authors have estimated acinar cell tumors to be as aggressive as ductal adenocarcinoma of the pancreas whereas other series showed acinar cell tumors to have a favorable clinical outcome. This discrepancy in prognosis may be related to the cellular components of the tumor. Methodology: With the aim to evaluate the possible relationship between the presence of neuroendocrine differentiation and behavior of these tumors, the authors reviewed all patients presenting acinar cell carcinoma of the pancreas in the last 5 years with emphasis in the immunohistochemical evaluation. Results: Four patients presented neuroendocrine differentiation on immunohistochemical evaluation and had a more benign outcome. Two patients without neuroendocrine component had a disseminated disease at presentation. This data suggests that this tumor is less aggressive than ductal adenocarcinoma and even with nodal involvement, long term survival after complete resection can be achieved. Conclusions: It is possible that the absence of neuroendocrine component may be related to a less favorable outcome and adjuvant therapy may be necessary. Due to the rarity of this pancreatic tumor, this relationship remains to be confirmed with a multicentric study including a larger number of patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Kaposi`s sarcoma-associated herpesvirus (KSHV) is endemic in the Amazon and rare in southern regions of Brazil. However, geographical distribution and epidemiological correlates of infection in this large country are still poorly defined. To estimate the seroprevalence of, and risk factors for, KSHV infection in Brazil, a multi-center study was conducted among 3,493 first-time voluntary unpaid blood donors from Salvador, Sao Paulo and Manaus. Antibodies against KSHV were detected using a whole-virus ELISA validated prior to the serosurvey. Antibodies against the latency-associated nuclear antigen (LANA) were detected by immuno-fluorescence assay (IFA) among ELISA-positive sera and a random sample of ELISA-negative sera. Overall, seroprevalence of KSHV by whole-virus ELISA was 21.7% (95% confidence interval (Cl): 20-23.4%) in men and 31.7% (95% Cl: 29-34.3%) in women (P<0.0001). KSHV antibodies were detected by IFA-LANA in 3% (95% Cl: 2-4.3%) of 867 ELISA-positive samples and in none of 365 randomly selected ELISA-negative samples. In multivariate analysis, KSHV seroprevalence by whole-virus ELISA was independently associated with female sex (odds ratio [OR] = 1.6, 95% Cl: 1.4-1.9); residence in the Amazon (OR = 1.4, 95% Cl: 1.2-1.8; compared to Salvador); Caucasian ethnicity (OR = 1.3, 95% Cl: 1.1-1.6) and herpes simplex virus type 2 (HSV-2) infection (OR = 1.3, 95% Cl: 1.1-1.6). KSHV seroprevalence did not significantly increase with age, nor was it associated with self-reported sexual behavior. KSHV seroprevalence is high among Brazilian blood donors, particularly from the Amazon region. This study supports the co-existence of sexual and non-sexual routes of KSHV transmission in this population.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Context: The expression of sodium iodide symporter (NIS) is required for iodide uptake in thyroid cells. Benign and malignant thyroid tumors have low iodide uptake. However, previous studies by RT-PCR or immunohistochemistry have shown divergent results of NIS expression in these nodules. Objective: The objective of the study was to investigate NIS mRNA transcript levels, compare with NIS and TSH receptor proteins expression, and localize the NIS protein in thyroid nodules samples and their surrounding nonnodular tissues (controls). Design: NIS mRNA levels, quantified by real-time RT-PCR, and NIS and TSH receptor proteins, evaluated by immunohistochemistry, were examined in surgical specimens of 12 benign and 13 malignant nodules and control samples. Results: When compared with controls, 83.3% of the benign and 100% of the malignant nodules had significantly lower NIS gene expression. Conversely, 66.7% of the benign and 100% of malignant nodules had stronger intracellular NIS immunostaining than controls. Low gene expression associated with strong intracellular immunostaining was most frequently detected in malignant (100%) than benign nodules (50%; P = 0.005). NIS protein was located at the basolateral membrane in 24% of the control samples, 8.3% of the benign, and 15.4% of the malignant nodules. The percentage of benign nodules with strong TSH receptor positivity (41.6%) was higher than malignant (7.7%). Conclusion: We confirmed that reduced NIS mRNA expression in thyroid malignant nodules is associated with strong intracellular protein staining and may be related to the inability of the NIS protein to migrate to the cellular basolateral membrane. These results may explain the low iodide uptake of malignant nodules.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Osteosarcoma is a malignant tumor of connective tissue Whose tumor cells produce bone tissue. It can be classified as osteoblastic, chondroblastic, or fibroblastic, according to the predominant histologic type of cells. Its dissemination is hematogenous; and the lungs are the most frequent site of clinically evident metastasis. Extrapulmonary metastases are rare and more frequently diagnosed at necropsy. We present a case of osteosarcoma with peritoneal dissemination that developed neoplastic ascites. Case A 46-year-old patient came to the hospital with a 4-month history of lumbar pain and weakness in the lower limbs. Computed tomography showed blastic lesions in the L3 vertebral body. Surgical resection and histologic analysis revealed a mixed osteoblastic and chondroblastic osteosarcoma. After only one session of chemotherapy, the patient presented a marked clinical worsening with extensive metastatic dissemination and occurrence of voluminous ascites. The cytologic examination of the ascitic fluid demonstrated frequent poorly differentiated tumor cells. The patient died a little more than 2 months after the diagnosis. Conclusion This case is the only report of osteosarcoma primarily focused on the vertebral column affected by peritoneal metastasis shown by cytologic examination of ascitic fluid. (Acta Cytol 2010;54:845-848)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Curative resection of pancreatic and biliary malignancies is rare. Most tumors are inoperable at presentation, and palliation of jaundice often is the goal. Biliary decompression can be achieved by surgical diversion or endoscopic biliary stents. This study aimed to compare clinical outcomes between surgical bypass and endoscopic uncovered nitinol stents in the palliation of patients with malignant distal common bile duct obstruction. Methods A multicenter, retrospective, cohort study investigated 86 patients with inoperable malignant distal common bile duct strictures at tertiary referral centers in Medellin, Colombia. These patients had undergone surgery (group 1) or placement of an uncovered 30-Fr self-expandable nitinol stent produced locally in Medellin, Colombia (group 2). The main outcome measurements included cumulative biliary patency, hospital stay, and patient survival. Results The study enrolled 86 patients (mean age, 66 years; range, 43-78 years) including 40 patients in group 1 and 46 patients in group 2. Both groups were similar in terms of age, gender, liver metastasis, and diagnosis. Technical success was achieved for 38 patients in group 1 (95%) and 43 patients in group 2 (93%). Functional biliary decompression was obtained in for 35 of the surgical patients (88%) and 42 of the stented patients (91%). Group 2 had lower rates for procedure-related mortality (2 vs. 7.5%; p = 0.01), a lower frequency of early complications (8.7 vs. 45%; p = 0.02), and a shorter hospital stay (median, 6 vs. 12 days; p = 0.01). Recurrent jaundice occurred for three patients in group 1 (7.5%) and eight patients in group 2 (17.3%) (p = 0.198). Late gastric outlet obstruction occurred for 12.5% of the patients in group 1 and 13% of the patients in group 2 (p = 0.73). Despite the early benefits of stenting, no significant difference in the median overall survival between the two groups was found (group 1, 163 days; group 2, 178 days; p = 0.11). The limitations of this study included the small number of patients and the retrospective design. Conclusions Endoscopic stenting and surgery are effective palliation. The former is associated with fewer early complications and the latter with fewer late complications. Patients who do not qualify for curative resection may be better managed by stent placement. Surgery should be reserved for patients more likely to survive longer.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thyroid cancer is the most frequent endocrine neoplasia worldwide. The route for metastasis and loco-regional invasion preferentially occurs by lymphatic vessels. For this reason, the assessment of lymphatic vessel density (LVD) is supposed to represent both a prognostic parameter and also a potential therapeutic target. In order to evaluate the value of LVD in benign and malignant thyroid lesions, we analyzed 110 thyroidectomy specimens using D2-40, a specific marker for lymphatic vessels and vascular endothelial growth factor C (VEGF-C), the most potent molecule of lymphatic proliferation. LVD was significantly different between papillary and follicular carcinomas in total (p = 0.045) and peritumoral area (p = 0.042). Follicular adenoma and follicular carcinoma showed an important difference of intra- (p = 0.019) and peritumoral (p = 0.033) LVD. VEGF-C was more markedly expressed in malignancies than in benignant lesions (p = 0.0001). Almost all cancers with high positive VEGF-C expression also exhibited increased peritumoral LVD (p = 0.049) when compared with the benignant lesions. Indeed, the high peritumoral LVD of malignant thyroid lesions is an important finding for surgery planning and supports the practice of total thyroidectomy in malignant thyroid neoplasm`s since the lymphatic peritumoral vessels definitely are an escape path for tumor cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: To describe the use of self-expandable metallic stents to manage malignant colorectal obstructions and to compare the radiation dose between fluoroscopic guidance of stent placement and combined endoscopic and fluoroscopic guidance. Materials and Methods: From January 1998 to December 2007, 467 oncology patients undergoing colorectal stent placement in a single center were included in the study. Informed consent was obtained in all cases. All procedures were performed with fluoroscopic or combined fluoroscopic and endoscopic guidance. Inclusion criteria were total or partial colorectal obstruction of neoplastic origin. Exclusion criteria were life expectancy shorter than I month, suspicion of perforation, and/or severe colonic neoplastic bleeding. Procedure time and radiation dose were recorded, and technical and clinical success were evaluated. Follow-up was performed by clinical examination and simple abdominal radiographs at 1 day and at I, 3, 6, and 12 months. Results: Of 467 procedures, technical success was achieved in 432 (92.5%). Thirty-five treatments (7.5%) were technical failures, and the patients were advised to undergo surgery. Significant differences in radiation dose and clinical success were found between the fluoroscopy and combined-technique groups (P < .001). Total decompression was achieved in 372 cases, 29 patients showed remarkable improvement, 11 showed slight improvement, and 20 showed clinical failure. Complications were recorded in 89 patients (19%), the most significant were perforation (2.3%) and stent migration (6.9%). Mean interventional time and radiation dose were 67 minutes and 3,378 dGy.cm(2), respectively. Conclusions: Treatment of colonic obstruction with stents requires a long time in the interventional room and considerable radiation dose. Nevertheless, the clinical benefits and improvement in quality of life justify the radiation risk.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Kaposi sarcoma (KS) is associated with human herpesvirus 8 (HHV-8). The cutaneous immune response in this tumour is not well established and a better understanding is necessary. Objectives To evaluate the HHV-8 expression and immune response in cutaneous lesions of classic KS (CKS) and AIDS-associated KS (AIDS-KS). Methods We performed a quantitative immunohistochemical study of cells expressing HHV-8 latency-associated nuclear antigen (LANA), CD4, CD8 and interferon (IFN)-gamma in skin lesions from patients with CKS and AIDS-KS (with or without highly active antiretroviral therapy, HAART). Results CKS showed higher LANA expression compared with AIDS-KS, regardless of HAART. We also found higher LANA expression in nodules compared with patch/plaque lesions. The tissue CD4+ cell proportion was lower in AIDS-KS patients without HAART than in patients with CKS. In CKS lesions, CD4+ and CD8+ cells expressed IFN-gamma, as shown by double immunostaining. AIDS-KS presented low numbers of IFN-gamma-expressing cells. CD8+ cell numbers were similar in all groups, which appeared unrelated to the clinical or epidemiological type of KS. Conclusions. Our quantitative data on the pattern of KS lesions in selected groups of patients, as shown by in situ immune response, demonstrated a CD4+ T-cell involvement associated with IFN-gamma, an environment of immune response-modified human immunodeficiency virus (HIV) infection. In our sample, the promotion of KS in patients without HIV appears to be related to higher HHV-8 load or virulence than in those with AIDS. This higher resistance may be explained by a sustained immune response against this herpesvirus, that is only partially restored but effective after HAART.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We report a case of a 17-year-old boy who had a giant congenital blue naevus with multiple satellite pigmented lesions. Later the patient developed melanoma arising in the pre-existing lesion. He also had gynaecomastia and was diagnosed as having aromatase excess syndrome. To our knowledge, the association of these two rare conditions has not been previously reported. Further studies should be performed to investigate this unusual combination, which may have a genetic, endocrine or local cutaneous link leading to its occurrence.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to analyze the effectiveness and safety of silver nitrate pleurodesis (SNP) in patients with recurrent malignant pleural effusion (RMPE) when performed in an outpatient setting. Prospective study including patients with RMPE recruited in a tertiary university-based hospital from February 2008 to June 2009. Elected patients underwent pleural catheter insertion (Day 1) followed by 0.5% SNP (Day 2), and on 7th day the drain was removed. All procedures were performed in an outpatient facility. Pleurodesis was considered successful when no additional pleural procedure was necessary by the 30th day. Complications were registered and graded according to the CTCAE3.0. Quality of life was evaluated before and 30 days after SNP. A total of 68 patients (54 female, 14 male, mean age: 57.3 years) were included. In addition, 7 had bilateral pleural effusions; therefore, 75 hemithoraces were drained. Also, 5 were excluded, and 70 hemithoraces (63 patients) underwent SNP. During the period of 30 days postpleurodesis, 8 deaths not related to the procedure occurred, and we lost contact with 10 patients who were followed elsewhere. At the 30th day, 48 hemithoraces (45 patients) were reevaluated, and 2 recurrences observed. The most frequent complication was pain-graded as 3 or more in 7 patients; infection occurred in 2 patients. Physical and environmental aspects of quality of life improved significantly after pleurodesis. In this study, SNP could be performed safely in an outpatient setting, with pain the most frequent complication. Recurrences occurred in 4% of the patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Anaplastic astrocytomas (AA) and glioblastomas (GB) are the most common malignant gliomas, and despite newly developed drugs and combined treatments, they still have an adverse prognosis. Paclitaxel is a cytotoxic agent with radiosensitizing properties and exerts objective growth inhibition in glioma tumor cells. Patients and Methods: From 1998 to 2002, 61 microneuro-surgically treated patients were randomized to group I (18 GB, 14 AA) which received radiotherapy and weekly paclitaxel at dose of 100 mg/m(2), and group II (21 GB, 8 AA) which received only radiotherapy as a complementary treatment. Results: Median overall survival was 27.96 months in group I and 23.06 months in group II with no statistical difference. The 12-month survival was 81% in group I and 76% in group II. Kaplan-Meier curves of both groups did not demonstrate any difference. Analysis of each histological subgroup (AA or GB) also showed no statistical difference in the survival curves. All 427 cycles were well tolerated with no treatment-associated deaths. Conclusions: Chemoradiotherapy with weekly paclitaxel is safe and tolerable although there was no increase in the overall survival and 12-month survival of malignant glioma patients. Further investigations modulating the paclitaxel entrance and delivery into the brain should be encouraged.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cytogenetic Studies of childhood ovary tumors have been poorly described. in the present article, the cytogenetic findings of an ovarian teratoma with malignant germ cell (yolk-sac) component occurring in an 8-year-old female are detailed. GTG-banding showed a karyotype of 46,XX, t(3;20)(q27;q13.3) [4]/46,XX, del3q27 [3]/46,XX [30]. Previous Studies have demonstrated common sites of loss of heterozygosity at 3q27-q28 region in different types of cancer, suggesting the presence of tumor Suppressor genes within this region. Pediatr Blood Cancer 2009;52:398-401. (C) 2008 Wiley-Liss, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Prostatic stromal tumours are rare neoplasias that include benign, malignant and borderline lesions. Stromal tumour of uncertain malignant potential (STUMP) has been recently described and only a few reports exist in the literature. As a rare and distinct neoplasia, to date, there is no description of MRI findings of prostate STUMP. In this article, we describe the clinical and MRI features with histopathological correlation of a patient with prostate STUMP.