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At least 523 records · Page 29Linked to original sources
PubMed2001

Fibroma (myxoma) molle in a hamster (Mesocricetus auratus).

An adult female Syrian hamster (Mesocricetus auratus) presented with a large, ulcerated lesion in its right cheek pouch; this wound interfered with the animal's ability to masticate. As a result, the hamster became inappetant and lethargic and lost about 25% of its original body weight within 6 to 9 weeks of presentation. The mass was surgically excised and submitted for histopathological evaluation. Microscopically, the mass was characterized as a neoplastic process partially encapsulated with fibrous connective tissue in the submucosa. Loosely arranged bundles of spindle to stellate cells with round to oval hyperchromatic nuclei and amphophilic cytoplasm were abundant. Some cells had multiple nucleoli, and some mitotic figures were observed. Special stains were used to definitively diagnose fibroma (myxoma) molle, a rare spontaneous neoplastic lesion in the hamster.

Animals↗
PubMedDate not supplied

[Hepatic involvement in pediatric neoplasms].

The liver is an organ which appears particularly susceptible to undergo a series of toxic effects related to the presence of a neoplastic process and the modalities adopted for its treatment. However, the phenomena of liver toxicity which are encountered at diagnosis and during treatment of pediatric neoplasias, are numerous and of complex nature, quite often of difficult explanation. The authors have distinguished: - primitive benign and malign tumors of the liver; - toxic effects dependent from the neoplastic infiltration of tumors arising in extrahepatic sites; - toxicity not related to neoplastic infiltration. Several cases of different solid neoplasias are described, which exemplify the several modes by which the liver can be affected by tumors, and the possible etiopathogenetic mechanisms are searched for. In addition, the authors refer on the aspects of liver toxicity observed in a series of 44 children affected by acute lymphoblastic leukemia. They distinguish a toxicity which precedes treatment; - a toxicity which arises during the induction-consolidation phase of therapy; - a toxicity which comes out during maintenance with Methotrexate and 6-mercaptopurine, this latter strictly correlated to the continuous administration of these two drugs. Finally, the complicated correlation between acute hepatitis and leukemia is discussed, and the attention is focused particularly on the possible antileukemic affect of the acute liver infection, which is capable to determine, in few well described cases, a complete, although transient disease remission.

Age Factors↗
PubMed1996

[Lymph node excision in cancer of the esophagus].

This paper analyses the surgical literature devoted to lymph node clearance for cancer of the esophagus. Involvement of a small number of lymph nodes by the neoplastic process does not preclude long-term survival and even cure. The superiority of the 3-field dissection over the 2-field dissection, although suggested in the available studies, should be confirmed by a prospective randomized study. Extensive lymph node clearance protects many patients from local recurrence, and allows to staging of the neoplastic disease and selection of those patients who are eligible for adjuvant therapy.

Belgium↗
PubMed1986

A comparative ultrastructural study of cutaneous blue naevi of humans and hamsters.

A comparative study of 12 human blue naevi and 15 carcinogen-induced hamster blue naevi showed no significant ultrastructural difference between these two groups of tumours. Both groups of tumours showed melanotic and hypomelanotic variants, and both were composed almost entirely of cells acceptable as melanocytes and melanophages. However, a few cells in some human and hamster tumours were partially or completely surrounded by a slender or quite thick external lamina. This may indicate a tendency towards a schwannocytic type of differentiation, but no other feature of schwannocytic differentiation such as the formation of mesaxons or pseudomesaxons was detected. Several cutaneous nerves were embedded in some of these tumours but they were clearly uninvolved in the neoplastic process and there was no evidence whatsoever that the tumours had developed from neural elements. We conclude that both human and hamster blue naevi are essentially melanocytomas which develop from dermal melanocytes which failed to reach the epidermis during development. We regard the occasional occurrence of an external lamina as an aberration of the neoplastic state which reflects the close kinship of melanocytes and Schwann cells i.e. their common origin from the neural crest.

Animals↗
PubMed1992

Cancer and pregnancy.

The diagnosis of cancer rarely complicates pregnancy. Despite the fact that advanced disease is often encountered, there is no scientific evidence that the pregnant state alters the neoplastic process. Only through careful attention to the patient can the clinician detect cancer at an early stage and offer the patient reasonable hope for a cure.

Female↗
PubMed1996

[Pediatric oncology: unity of science and clinic].

The paper outlines progress made in pediatric oncology in Russia in the past 30 years. Studies dealing with the clinical presentation, diagnosis, and treatment of malignant neoplasms in children have revealed great differences in the clinical course of malignant processes in childhood due to anatomic and physiological features of a child's developing organism and to the prevalence of more aggressive and high-grade tumors--sarcomatous and germinogenic. In children, most tumors are congenital. The influence of exogenous and endogenous factors on the mother and the fetus brings about either fetal death, or a neoplastic process of developmental malformations and more frequently their combination.

History, 20th Century↗
PubMed1998

Extrapulmonary inflammatory myofibroblastic tumor: a clinical and pathological survey.

Inflammatory myofibroblastic tumor (IMT) or inflammatory pseudotumor was initially recognized in the lung, and somewhat later, a similar-appearing pathological process was reported in the liver. Presently, this tumor has been described in virtually all major organs and extrapulmonary sites with a few exceptions. It was thought initially that the IMT was nonneoplastic and represented an aberrant inflammatory response despite its gross and microscopic features of a spindle cell neoplasm. The inflammatory hypothesis about the pathogenesis has been more readily accommodated in the lung than in the extrapulmonary sites of involvement. Some cases, however, were accompanied by the constitutional symptoms and signs of an inflammatory process, which resolved in most cases after surgical resection. There were some pathological aspects of the IMT that seemingly contradicted its purely inflammatory nature, including its potential for local recurrence; development of multifocal, noncontiguous tumors; infiltrative local growth; vascular invasion; and malignant transformation. These pathological features seemed to support the hypothesis that the IMT is a neoplastic process, which has been augmented by reports that these tumors have clonal characteristics. Other studies have suggested that IMTs of the liver and spleen are associated with the Epstein-Barr virus. From the diagnostic perspective, there are several potential difficulties that the pathologist may encounter in the examination of one of these tumors. Just as it was true 60 years ago, the potential for a pathological diagnosis of one or another type of spindle cell sarcoma has not diminished with time. Because these tumors have a predilection for children, embryonal rhabdomyosarcoma is another diagnostic temptation when an IMT presents in the bladder or other hollow viscus. The IMT should probably be regarded as a soft tissue-mesenchymal tumor with an indeterminant or low malignant potential, which is a somewhat indefinite but realistic prognostic category.

Cytogenetics↗
PubMed1988

A morphological analysis endocrine tumour genesis in pancreas and anterior pituitary of AVP/SV40 transgenic mice.

Insertion into the mouse genome of the hybrid oncogene made up of bovine vasopressin gene derived 5' upstream sequences and the coding sequences of SV40 large T-antigen promoted tumours in anterior pituitary and endocrine pancreas of mice bearing this transgene. In order to investigate the morphology of the steps in the neoplastic process, we used light and electron microscopy to study these organs in 42 animals belonging to the 3rd, 4th and 5th generations, subdivided into 4 age groups from 20 days to 100 days of life. Antibodies to large T-antigen were used to identify sites of expression of the hybrid oncogene, thus monitoring the steps in neoplastic transformation. Large T-antigen immunoreactivity was identified in dysplastic lesions of younger animals and in both dysplastic lesions and tumours of older mice. Insulin (100% of cases) and pancreatic polypeptide (25% of cases) immunoreactivities were revealed in pancreatic lesions but no hormonal immunoreactivity was detected in the pituitary lesions. The ultrastructural study confirmed that the majority cell population of the pancreatic neoplasms was B-type and that the anterior pituitary tumours were poorly granulated. The subcellular localization of large T-antigen immunoreactivity was investigated by the immunogold method and was confined to the heterochromatin of tumour cell nuclei. These findings provide evidence for the dysplasia-neoplasia sequence in the genesis of endocrine tumours of pituitary and pancreas of transgenic mice. The vasopressin-SV40 large T-antigen transgenic mice may therefore be an useful model for the study of endocrine cell oncogenesis.

Animals↗
PubMed1998

Inherited predisposition to colon cancer.

Colorectal cancer is one of the most common malignancies in the United States. Although both genetic and environmental factors play a role in colorectal tumorigenesis, recent advances in genetics have more clearly defined the impact of inheritance in the multistep process of the disease. Researchers have identified single genes that confer a susceptibility to familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). Because these genes are inherited in an autosomal dominant fashion, offspring of carriers have a 50% chance of inheriting the gene mutation and its associated risk. The FAP gene, when mutated, initiates the neoplastic process. HNPCC gene mutations disrupt mismatch repair, thus inducing progression of tumor formation. Discovery of these genes has helped our understanding of sporadic colon cancer as well. Genetic testing for the FAP and HNPCC genes is now available, and results of this testing have implications for surveillance and management. In addition, testing raises complex psychosocial and ethical issues. At present, genetic testing is primarily conducted in the research setting, but it will soon be available in the clinical arena. To prepare for the challenges that these new advances will present, nurses must begin now to enhance their knowledge of genetics and its application to oncology.

Adenomatous Polyposis Coli↗
PubMed2006

Acute, subacute, and chronic cervical lymphadenitis in children.

Lymphadenopathy refers to any disease process involving lymph nodes that are abnormal in size and consistency. Lymphadenitis specifically refers to lymphadenopathies that are caused by inflammatory processes. Cervical lymphadenopathy is a common problem in the pediatric age group and is largely inflammatory and infectious in etiology. Although most patients are treated successfully by their primary care physician, surgical consultation is frequently required for patients who fail to respond to initial therapy or for those in whom there is an index of suspicion for a neoplastic process. This article addresses current approaches to the diagnosis and management of cervical lymphadenitis in children.

Acute Disease↗
PubMed1997

Utility of tumour markers in the diagnosis of neoplastic pleural effusion.

Approximately 20% of pleural effusions are caused by neoplastic processes. Although cytology is the most specific routine diagnostic procedure, its sensitivity of 50-60% is insufficient, and thus diagnosis is usually carried out by more invasive techniques such as pleural biopsy, thoracoscopy or thoracotomy. The object of this study is to evaluate the use of determining some tumour markers in pleural fluid obtained by thoracocentesis for diagnosis of neoplastic pleural effusion. Patients (271) with pleural effusions were classified in five groups: I: neoplasms n = 88; II: tuberculosis n = 63; III: parapneumonics n = 53; IV: miscellaneous exudates n = 39 and V: transudates n = 28. The tumour markers studied were: carcinoembryonic antigen (CEA), CA 125, squamous cell carcinoma antigen (SCC), and neuron specific enolase (NSE). The tumour makers had the following diagnostic efficiencies for neoplastic origin of the pleural effusion: CEA 76% (sensitivity 31%, specificity 93%); CA 125 66% (70% and 61%); SCC 65% (48% and 80%) and NSE 53% (30% and 89%). The diagnostic efficiencies for pulmonary neoplastic origins were 68% for NSE (sensitivity 83%, specificity 53%); 65% for SCC (54% and 75%); 63% for CEA (80% and 48%) and 61% for CA 125 (79% and 42%). We believe that the routine testing of tumour markers in pleural fluid obtained by thoracocentesis would greatly increase diagnostic effectiveness and could avoid the practice of more aggressive diagnostic techniques on the patient.

Antigens, Neoplasm↗
PubMed1999

Field cancerization, clonality, and epithelial stem cells: the spread of mutated clones in epithelial sheets.

There has been considerable debate about the origin of human tumours, whether they arise from a single cell and are clonal populations or whether there needs to be some sort of co-operativity between cells for the neoplastic process to begin. Current theories subscribe to the clonal view, where a series of mutations in one cell begins a process of selection and clonal evolution leading to the development of the malignant phenotype. This review approaches this problem by asking how mutated clones, once established, spread through tissues before becoming overtly invasive. While there is substantial evidence in favour of independent origins of each tumour from a unique mutated clone, there are instances where such clones expand and remain cohesive, often involving a large area of tissue. The main example is the movement of mutated clonal crypts through the colorectal epithelium, by the process of crypt fission. In passing, the clonal architecture of early, pre-invasive lesions is examined, often with some surprising results.

Animals↗
PubMed2002

Ikaros gene expression and leukemia.

The Ikaros (Ik) protein, or LyF1, was initially described as a protein binding to regulatory sequences of a number of genes expressed in murine lymphoid cells. Ikaros is a critical regulator of normal hematopoietic stem cell differentiation, as evidenced by dramatic defects in the lymphoid compartments, in homozygous animals with gene inactivation. Because differential splicing produces multiple isoforms with potentially different functions, Ikaros provides a unique model to study how post-transcriptional mechanisms may be involved in neoplastic processes. Indeed, several groups including ours have underlined evidences that expression of different Ikaros isoforms vary among different types of leukemias. The predominance of short isoforms in certain subsets is intriguing. Here, additional observations reinforced the hypothesis that Ikaros expression may be deregulated in human leukemias. Whether this is a cause or a consequence of the leukemic process remains speculative. Other human diseases however, provide examples of abnormal post-transcriptional regulations that have been further characterized.

Alternative Splicing↗
PubMedDate not supplied

17 beta-estradiol-regulated expression of protein tyrosine phosphatase gamma gene in cultured human normal breast and breast cancer cells.

BACKGROUND: Protein tyrosine phosphatase gamma (PTP gamma) has been implicated as a potential tumor suppressor gene in kidney and lung adenocarcinomas. We have previously shown that PTP gamma mRNA expression levels are lower in DES-induced kidney tumors than in normal kidneys of Syrian hamsters. The goals of the present study were to determine if PTP gamma mRNA is present in both normal and cancerous human breast cells, and to investigate the estrogenic regulation of PTP gamma mRNA expression in these cell types. METHODS: Primary cultured human breast cells derived from surgical specimens of mammoplasty and breast cancer patients, as well as human breast cancer cell lines were used for the study. RT-PCR and RNase protection assay was utilized to detect and quantify levels of PTP gamma mRNA among the cell types used and between control and 17 beta-estradiol (E2)-treated cells. Transient transfection of human estrogen receptor (ER) into MDA-MB-231 human breast cancer cells was performed to establish the role of ER in the regulation of PTP gamma mRNA expression. RESULTS: The results show that PTP gamma mRNA is expressed in primary cultured human breast cells isolated from mammoplasty and breast cancer patients, as well as in human cancer cell lines, and that E2 significantly inhibits PTP gamma expression in ER-positive human breast cancer cells via an ER-mediated mechanism. We show that PTP gamma mRNA levels are lower in human breast cancer cells than in normal human breast cells. Furthermore, we report that PTP gamma mRNA expression is inhibited by E2 in a dose-dependent manner in primary cultured breast cells. After treatment with 20 nM E2 for 24 hours, PTP gamma mRNA was significantly suppressed in primary cultured cancerous and non-cancerous cells from breast cancer patients, as well as in the ER-positive MCF-7 cell line by 50%, 85%, and 66%, respectively. In contrast, the PTP gamma mRNA expression levels did not change in similarly treated ER-negative MDA-MB-231 cells. Sensitivity to E2-induced suppression could be restored (94% inhibition) by transfecting MDA-MB-231 cells with an ER expression plasmid. CONCLUSIONS: Our results are the first to suggest that PTP gamma is a potential estrogen-regulated tumor suppressor gene in human breast cancer which may play an important role in neoplastic processes of human breast epithelium.

Breast↗
PubMed1975

Effects of methanol extraction residue and therapeutic irradiation against established isografts and simulated local recurrence of mammary carcinomas.

Female BALB/c mice carrying established isografts or simulated local recurrence implants of 2 rapidly growing mammary adenocarcinomas were treated either by injection of the methanol extraction residue (MER) fraction of killed Bacillus Calmette-Guérin organisms (given s.c. or into the tumor) or by focal X-irradiation or by both. None of the modalities of therapy effected cures, but in many instances there was a significant retardation of tumor cevelopment and prolongation of the lives of the mice. Administration of MER alone offered protection in a number of cases but less often than the other forms of treatment. Combined therapy with MER and irradiation was, on the whole, the most successful therapeutic intervention. MER or irradiation administered alone enhanced the neoplastic process only on rare occasions; this appeared to be the case even more infrequently with combined treatment. MER was most likely to be effective alone or in combination when small quantities were used and when only 1 treatment or 1 cycle of combined therapy was given. The therapeutic action of MER was not dependent on direct introduction of the agent into a neoplastic focus; s.c. administration distal to the tumor site was almost always at least as satisfactory as injection directly into the tumor mass and indeed was often more efficacious.

Adenocarcinoma↗
PubMed2004

Adult human mesenchymal stem cell as a target for neoplastic transformation.

The neoplastic process may involve a cancer stem cell. This concept has emerged largely from the careful analysis of tumour biopsy systems from haematological, breast and brain tumours. However, the experimental systems necessary to provide the cellular and molecular evidence to support this important concept have been lacking. We have used adult mesenchymal stem cells (hMSC) transduced with the telomerase hTERT gene to investigate the neoplastic potential of adult stem cells. The hTERT-transduced line, hMSC-TERT20 at population doubling level (PDL) 256 showed loss of contact inhibition, anchorage independence and formed tumours in 10/10 mice. hMSC-TERT4 showed loss of contact inhibition at PDL 95, but did not exhibit anchorage independence and did not form tumours in mice. Both lines had a normal karyotype but showed deletion of the Ink4a/ARF locus. At later passage, hMSC-TERT4 also acquired an activating mutation in KRAS. In hMSC-TERT20, expression of the cell cycle-associated gene, DBCCR1 was lost due to promoter hypermethylation. This epigenetic event correlated with acquisition of tumorigenicity. These data suggest that the adult hMSCs can be targets for neoplastic transformation and have implications for the development of novel anticancer therapeutics and for the use of hMSC in tissue engineering and transplantation protocols.

Adult↗
PubMed2004

Extrapulmonary tuberculosis as a mimicker of neoplasia.

Despite the efforts for control and eradication of tuberculosis, new cases of the disease are diagnosed daily. The diagnosis of tuberculosis is easily made when the classical features of pulmonary necrotizing granulomatous inflammation are seen. However, extrapulmonary lesions may clinically and radiographically mimic a neoplastic process, and this may lead to misdiagnosis and delay in treatment. We studied 6 patients by aspiration biopsy, all recent immigrants and immunocompetent, who presented with weight loss and fatigue. Of these, 5 patients had a mass. One patient presented with a lytic lesion of bone. In all cases the clinical diagnosis was neoplasia. In all aspirates, the smears showed necrotic debris with neutrophils. No neoplastic cells or granulomas were seen. All cases were signed out descriptively with no specific diagnosis. A search for acid-fast organisms leading to the correct diagnosis of tuberculosis was prompted by clinical investigations that revealed pulmonary lesions, or by repeat aspiration biopsy, which showed granulomatous inflammation. Tuberculosis when present in atypical forms is still a challenging diagnosis. The finding of necrotic debris in a needle biopsy without the clinical signs of an abscess should prompt a search for acid-fast bacilli, since the correct diagnosis will eliminate a needless surgical procedure and will lead to timely and appropriate therapy.

Adult↗
PubMed1986

Magnetic resonance imaging of the pelvis: prostate and urinary bladder.

Magnetic resonance imaging has opened up a new horizon in the evaluation of the male pelvis. Its direct multiplanar imaging and display of the unique tissue contrast allows for the demonstration of prostate anatomy. Prostatic disease, even when confined to the gland, is easily depicted. However, one cannot distinguish benign from malignant processes. In a patient with a known prostatic neoplasm, magnetic resonance is useful as a staging modality. Accuracy in the staging of prostatic malignancies by MRI surpasses that of ultrasound or CT. In the evaluation of the urinary bladder, the greatest advantage of magnetic resonance is its ability to differentiate between a normal bladder, and other pathologic conditions affecting the bladder, including inflammatory, congestive and neoplastic processes. In the evaluation of bladder carcinoma, magnetic resonance is useful as a staging modality. Clinical application of magnetic resonance is just beginning and therefore, the full potential of the modality has yet to be explored.

Adult↗