919 resultados para Benign tumors


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This report describes a rare case of coexistence of benign phyllodes tumor, which measured 9 cm in the right breast, and invasive ductal carcinoma of 6 cm in the left breast, synchronous and independent, in a 66-year-old patient. The patient underwent a bilateral mastectomy due to the size of both lesions. Such situations are rare and usually refer to the occurrence of ductal or lobular carcinoma in situ when associated with malignant phyllodes tumors, and more often in ipsilateral breast or intra-lesional.

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Backgroud: Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case.Case presentation: Hematopoietic stem cells were found in a benign mixed mammary tumor of a 7-year-old female mongrel dog that presents a nodule in the left inguinal mammary gland. The patient did not have any hematological abnormalities. Cytological evaluation demonstrated two distinct cell populations, composed of either epithelial or mesenchymal cells, sometimes associated with a fibrillar acidophilic matrix, apart from megakaryocytes, osteoclasts, metarubricytes, prorubricytes, rubricytes, rubriblasts, promyelocytes, myeloblasts. Histological examination confirmed the presence of an active hematopoietic bone marrow within the bone tissue of a benign mammary mixed tumor.Conclusions: EMH is a rare condition described in veterinary medicine that can be associated with mammary mixed tumors. It's detection can be associated with several neoplastic and non-neoplastic mammary lesions, i.e. osteosarcomas, mixed tumors and bone metaplasia.

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Benign and malignant thyroid tumors constitute a wide range of neoplasias showing recurrent chromosome abnormalities. In an attempt to characterize specific numerical chromosome abnormalities in thyroid tissues, We present here the findings from a study of archival samples depicted by 10 malignant tumors, 30 benign lesions, and 10 normal thyroid tissues. Fluorescence in situ hybridization was performed on noncultured samples using biotinylated centromere-specific probes for chromosomes 7, 10, and 17. Trisomy or tetrasomy 7 were present in 19 benign and in 7 malignant tumors. Trisomy 10 or 17 were observed in 18 adenomas or goiters and in 9 carcinomas, and monosomy 17 was seen in 2 carcinomas. Our findings suggest that such abnormalities are an in vivo phenomenon and may be important in the neoplastic proliferation of thyroid gland. (C) Elsevier B.V., 2000. All rights reserved.

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PURPOSE:To assess whether late introduction of a specific COX-2 inhibitor (Meloxicam) can treat and/or prevent the progression of tumors in the stomach of rats submitted to duodenogastric reflux. METHODS: Seventy five male Wistar rats, weighing 150 grams, were submitted to the induction of duodenogastric reflux through the pylorus. At 36 weeks of follow-up were established three experimental groups: DGR36 sacrificed immediately, DGR54 and DGR54MLX both sacrificed at 54th week of follow-up . The animals of the latter group were fed with a rat chow premixed with Meloxicam (2.0 mg/ kg feed; 0.3 mg / kg bw / day) and the other two with standard rat chow. The lesions found in the pyloric mucosa and gastrojejunal anastomosis were analyzed macroscopically and histologically. For statistical analysis was adjusted a generalized linear model assuming a binomial distribution with LOGIT link function. RESULTS: No significant differences were found when comparing the incidences of benign tumor lesions (Adenomatous Hyperplasia), p=0.4915, or malignant (Mucinous Adenocarcinoma), p=0.2731, among groups. CONCLUSION: Late introduction of specific COX-2 inhibitor (Meloxicam) did not treat and was not able to prevent the progression of tumoral lesions induced by duodenogastric reflux in the rat stomachs.

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Cytology is a well established research technique in human and veterinary medicine, but it is rarely used in small rodents. Spontaneous tumors are relatively uncommon in guinea pigs and those described in literature include a variety of organs like skin and subcutis, respiratory and reproductive tract, endocrine and hematopoietic system, and mammary gland. The objective of this article was to describe the use of the fine needle aspiration biopsy technique (FNAB) on evaluation of a mammary neoplasm in a guinea pig and describe the main cytological findings for the first time in literature.

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Background: To establish the best methodology for diagnosis and management of patients with solid and complex renal masses by comparing the costs and benefits of different imaging methods and to improve differential diagnosis of these benign and malignant lesions, particularly by investigating tumour calcifications. Methods: We performed a prospective study on 31 patients with solid or complex masses by submitting them to Abdominal Ultrasonography (US), Doppler Ultrasonography of the renal mass (US Dop), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI). Results: We found 28 patients with malignant and three with benign masses. Of the 28 malignant, 17 showed calcifications at CT; 16 central and one was of the pure peripheral curvilinear type (egg shell). Excretory Urography (IVP) had a significantly lower detection rate for central calcifications than both US and CT. Benign and malignant masses appeared as described in literature, with US, CT and MRI showing high sensitivity and specificity in renal tumor diagnosis. The exception was US Dop where we obtained lower sensitivity for the characterization of malignant tumor flow. Conclusions: In this series we were surprised to find that CT revealed central calcifications in 51.6% of patients, all with malignant lesions, while, literature reports a frequency of calcification in renal cell carcinoma between 8 and 22%, in studies using abdominal films and EU (IVP). This finding is of great importance when we consider that these calcifications occur particularly in malignant neoplasms. As a result of comparing these different imaging methods we have developed a better methodology for renal tumor investigation.

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Objective. The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs). Study Design. The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT). Results. KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1. Conclusions. MMP-9, TIMP-2, EGF and transforming growth factor alpha act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:487-496)

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This report describes a rare case of coexistence of benign phyllodes tumor, which measured 9 cm in the right breast, and invasive ductal carcinoma of 6 cm in the left breast, synchronous and independent, in a 66-year-old patient. The patient underwent a bilateral mastectomy due to the size of both lesions. Such situations are rare and usually refer to the occurrence of ductal or lobular carcinoma in situ when associated with malignant phyllodes tumors, and more often in ipsilateral breast or intra-lesional.

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Perineurioma is an uncommon, mostly benign, spindle-cell tumor of peripheral nerve sheath origin with a predilection for the soft tissues. Although increasing awareness points to the sites of involvement by perineurioma possibly being as ubiquitous as those frequented by schwannian tumors, only one intracerebral example has been described to date. We report on a surgically resected perineurioma of the falx cerebri in an 86-year-old woman. Preoperative imaging showed an enhancing extraaxial mass of 6 cm × 5.7 cm × 3.7 cm. Histologically, the tumor consisted of a proliferation of spindle cells interwoven by a lattice of basal lamina. Alongside a prevailing soft tissue perineurioma pattern, sclerosing and reticular areas were seen as well. Tumor cells coexpressed EMA and GLUT-1, and a minority immunoreacted for smooth muscle actin. Pericellular basal lamina was decorated with collagen type IV. No staining for S100 protein was detected. Mitotic activity was virtually absent, and the MIB1 labeling index averaged 2%. Ultrastructural examination revealed abundant pinocytotic vesicles within and conspicuous tight junctions between slender cytoplasmic processes which, in turn, were encased by discontinuous basal lamina. FISH analysis confirmed loss of at least part of one chromosome 22q. This observation calls attention to perineurioma as a novel item in the repertoire of low-grade meningial spindle cell neoplasms, in the differential diagnostic context of which it is apt to being misconstrued as either meningioma, solitary fibrous tumor, or neurofibroma. Confusion with the latter bears the risk of overgrading innocuous features of perineurioma as criteria for malignancy.

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Malignant mesodermal tumors of the uterus are an inhomogenous group of uterine malignancies with different pathogenesis, clinical presentation and prognosis. These rare tumors represent approximately 1 % of all uterine malignancies. The aggressive carcinosarcomas or mixed muellerian tumors are defined by mixed malignant epithelial and malignant mesodermal histopathology and are of the same precursor cell origin like endometrial cancer. Thus, carcinosarcomas were reclassified by the FIGO as an aggressive type of endometrial cancer and treated like type II endometrial cancer. Adenosarcomas are also mixed tumors with benign epithelial proliferation and malignant mesodermal cell growth, have a good prognosis and represent less than 5 % of all mesodermal uterine malignancies. Besides carcinosarcomas, the pure mesodermal leiomyosarcomas are the most common mesodermal malignancies. Patients with leiomyosarcamos are usually perimenopausal, and although more than half of the patients present with symptoms, diagnosis occurs incidentally in most cases in final histopathologic workup of an excised putative myoma or uterus. Adequate anamnesis, gynecologic examination and careful imaging by transvaginal ultrasound in the preoperative setting might hint to correct differential diagnosis in many cases. Overall the prognosis of uterine leiomyomas is poor. Malignancies of the endometrial stroma are very rare and divided in two subgroups, the mostly estrogen receptor positive endometrial stromal sarcoma, which occur preferably in premenopausal women and show a favorable prognosis, and the very aggressive undifferentiated endometrial sarcomas. The more rare undifferentiated endometrial sarcomas occur in postmenopausal women and most patients die in the first two years after diagnosis. Risk stratification of preoperative differential diagnosis requires improvements and the correct histopathologic workup of mesodermal uterine malignancies is still a challenge for pathologists.

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Myoepithelioma is a dimorphic neoplasm with contractile-epithelial phenotype, originally interpreted as deriving from, but not actually restricted to the salivary glands. As a novel addition to the list of exquisitely rare intracranial salivary gland-type tumors and tumor-like lesions, we report on an example of myoepithelioma encountered in the left cerebellopontine angle of a 32-year-old male. Clinically presenting with ataxia and dizziness, this extraaxial mass of 4 × 3.5 × 3 cm was surgically resected, and the patient is alive 6 years postoperatively. Histologically, the tumor exhibited a continuum ranging from compact fascicles of spindle cells to epithelial nests and trabeculae partitioned by hyalinized septa, while lacking tubular differentiation. Regardless of architectural variations, there was robust immunoexpression of S100 protein, smooth muscle actin, GFAP, cytokeratin, and vimentin. Cytologic atypia tended to be modest throughout, and the MIB1 labeling index averaged less than 1%. Fluorescent in situ hybridization indicated no rearrangement of the EWSR1 locus. We interpret these results to suggest that myoepithelioma of the posterior fossa - along with related salivary epithelial tumors in this ostensibly incongruous locale - may possibly represent analogous neoplasms to their orthotopic counterparts, ones arising within aberrant salivary anlagen. The presence of the latter lends itself to being mechanistically accounted for by either postulating placodal remnants in the wake of branchial arch development, or linking them to exocrine glandular nests within endodermal cysts. Alternatively, myoepithelioma at this site could be regarded as a non tissue-specific lesion similar to its relatives ubiquitously occurring in the soft parts.

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The prognosis of pancreatic neuroendocrine tumors is related to size, histology and proliferation rate. However, this stratification needs to be refined further. We conducted a proteome study on insulinomas, a well-defined pancreatic neuroendocrine tumor entity, in order to identify proteins that can be used as biomarkers for malignancy. Based on a long follow-up, insulinomas were divided into those with metastases (malignant) and those without (benign). Microdissected cells from six benign and six malignant insulinomas were subjected to a procedure combining fluorescence dye saturation labeling with high-resolution two-dimensional gel electrophoresis. Differentially expressed proteins were identified using nano liquid chromatography-electrospray ionization/multi-stage mass spectrometry and validated by immunohistochemistry on tissue microarrays containing 62 insulinomas. Sixteen differentially regulated proteins were identified among 3000 protein spots. Immunohistochemical validation revealed that aldehyde dehydrogenase 1A1 and voltage-dependent anion-selective channel protein 1 showed significantly stronger expression in malignant insulinomas than in benign insulinomas, whereas tumor protein D52 (TPD52) binding protein was expressed less strongly in malignant insulinomas than in benign insulinomas. Using multivariate analysis, low TPD52 expression was identified as a strong independent prognostic factor for both recurrence-free and overall disease-related survival.

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CSPG4 marks pericytes, undifferentiated precursors and tumor cells. We assessed whether the shed ectodomain of CSPG4 (sCSPG4) might circulate and reflect potential changes in CSPG4 tissue expression (pCSPG4) due to desmoplastic and malignant aberrations occurring in pancreatic tumors. Serum sCSPG4 was measured using ELISA in test (n = 83) and validation (n = 221) cohorts comprising donors (n = 11+26) and patients with chronic pancreatitis (n = 11+20) or neoplasms: benign (serous cystadenoma SCA, n = 13+20), premalignant (intraductal dysplastic IPMNs, n = 9+55), and malignant (IPMN-associated invasive carcinomas, n = 4+14; ductal adenocarcinomas, n = 35+86). Pancreatic pCSPG4 expression was evaluated using qRT-PCR (n = 139), western blot analysis and immunohistochemistry. sCSPG4 was found in circulation, but its level was significantly lower in pancreatic patients than in donors. Selective maintenance was observed in advanced IPMNs and PDACs and showed a nodal association while lacking prognostic relevance. Pancreatic pCSPG4 expression was preserved or elevated, whereby neoplastic cells lacked pCSPG4 or tended to overexpress without shedding. Extreme pancreatic overexpression, membranous exposure and tissue(high)/sera(low)-discordance highlighted stroma-poor benign cystic neoplasm. SCA is known to display hypoxic markers and coincide with von-Hippel-Lindau and Peutz-Jeghers syndromes, in which pVHL and LBK1 mutations affect hypoxic signaling pathways. In vitro testing confined pCSPG4 overexpression to normal mesenchymal but not epithelial cells, and a third of tested carcinoma cell lines; however, only the latter showed pCSPG4-responsiveness to chronic hypoxia. siRNA-based knockdowns failed to reduce the malignant potential of either normoxic or hypoxic cells. Thus, overexpression of the newly established conditional hypoxic indicator, CSPG4, is apparently non-pathogenic in pancreatic malignancies but might mark distinct epithelial lineage and contribute to cell polarity disorders. Surficial retention on tumor cells renders CSPG4 an attractive therapeutic target. Systemic 'drop and restoration' alterations accompanying IPMN and PDAC progression indicate that the interference of pancreatic diseases with local and remote shedding/release of sCSPG4 into circulation deserves broad diagnostic exploration.

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In search of novel genes expressed in metastatic prostate cancer, we subtracted cDNA isolated from benign prostatic hypertrophic tissue from cDNA isolated from a prostate cancer xenograft model that mimics advanced disease. One novel gene that is highly expressed in advanced prostate cancer encodes a 339-amino acid protein with six potential membrane-spanning regions flanked by hydrophilic amino- and carboxyl-terminal domains. This structure suggests a potential function as a channel or transporter protein. This gene, named STEAP for six-transmembrane epithelial antigen of the prostate, is expressed predominantly in human prostate tissue and is up-regulated in multiple cancer cell lines, including prostate, bladder, colon, ovarian, and Ewing sarcoma. Immunohistochemical analysis of clinical specimens demonstrates significant STEAP expression at the cell–cell junctions of the secretory epithelium of prostate and prostate cancer cells. Little to no staining was detected at the plasma membranes of normal, nonprostate human tissues, except for bladder tissue, which expressed low levels of STEAP at the cell membrane. Protein analysis located STEAP at the cell surface of prostate-cancer cell lines. Our results support STEAP as a cell-surface tumor-antigen target for prostate cancer therapy and diagnostic imaging.