Loading...
(1/191) Walker 256/S carcinosarcoma causes osteoporosis-like changes through ectopical secretion of luteinizing hormone-releasing hormone.

We have shown that Walker 256/S mammary carcinoma caused osteoporosis-like changes in young female rats, accompanied by low serum estradiol and hypercalciuria without changes in the serum levels of calcium, phosphorus, and parathyroid hormone-related peptide. In this study, we investigated the cause of bone loss after Walker 256/S inoculation into female 6-week-old Wistar Imamichi rats, focusing on the sex hormone balance in the host animal. Walker 256/S-bearing rats showed characteristic osteoporosis, with a significant increase in spleen weight and a significant decrease in uterine weight by 14 days after s.c. tumor inoculation. In the in vitro bone marrow culture, mineralized nodule formation ability decreased according to the time after tumor inoculation, and tartrate-resistant acid phosphatase-positive multinucleated cell formation increased at 7 days after tumor inoculation, but it began to decrease at 14 days after tumor inoculation. This indicates that after inoculation with Walker 256/S tumor, the progenitors of osteoblasts and ostroclasts lost their balance in the bone turnover, resulting in bone resorption. On the other hand, Walker 256/S carcinoma expressed luteinizing hormone-releasing hormone (LH-RH) mRNA, and in Walker 256/S-bearing rats, the serum LH-RH level increased significantly from 3 days after tumor inoculation, whereas in the healthy control rats, this level was very low. Consequently, the serum levels of follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone were significantly lower in the tumor-bearing rats than in the healthy control rats. Because the LH-RH gene is located in the long prolactin release-inhibiting factor (PIF) gene and mRNA amplified by reverse transcription-PCR in this study contained whole LH-RH and a part of PIF, the Walker 256/S tumor is thought to express PIF. Indeed, the serum prolactin level decreased in tumor-bearing rats. The serum level of growth hormone, one of the other pituitary hormones, was not changed. Moreover, the level of an osteolytic cytokine, tumor necrosis factor alpha, increased in the serum of Walker 256/S-bearing rats, although this may be a result of the immune response of the host animal to tumor growth as well as an enlarged spleen. In conclusion, the Walker 256/S tumor lowers estrogen secretion through ectopical oversecretion of LH-RH, and then osteolytic cytokines, such as tumor necrosis factor alpha, increase in tumor-bearing rats, escape the control of estrogen, and activate osteoclasts, resulting in bone loss in a short period.  (+info)

(2/191) Classification and behavior of canine mammary epithelial neoplasms based on life-span observations in beagles.

As part of a study of the effects of low-level radiation, 1,343 Beagles, including 671 males and 672 females, were evaluated over their full lifetime for the occurrence of mammary neoplasia; there were 139 control males and 138 control females and 532 irradiated males and 534 irradiated females. All nodules found in surgical specimens or at necropsy were evaluated histologically. The overall incidence, metastasis and recurrence rates, and contribution to mortality of mammary neoplasms were determined. Based on this unique opportunity to correlate morphologic characteristics with ultimate biological behavior of all mammary tumors in a defined canine population, we propose a histogenetically based reclassification of epithelial mammary tumors. Of the 672 female dogs, 70.8% (476) had at least one mammary neoplasm; 60.7% (408) had more than one. Two male dogs had mammary neoplasms. Of 1,639 mammary carcinomas in the 672 females, 18.7% (307) were classified as ductular carcinomas (arising from the small interlobular or intralobular ductules), whereas 80.7% (1,322) were classified as adenocarcinomas of other histogenetic origin. Of 73 fatal carcinomas, ductular carcinomas accounted for 48 fatalities (65.8%), whereas other adenocarcinomas accounted for only 20 fatalities (27.4%). Radiation had no effect on this ratio. Ductular carcinomas also had a higher rate of metastasis than did adenocarcinomas. Existing classifications of mammary carcinomas do not recognize the characteristic morphologic features, the degree of malignancy, and the prognostic importance of these ductular carcinomas. Metastasis rates did not differ between simple and complex carcinomas or between those lesions and adenocarcinomas in mixed tumors. True carcinosarcomas metastasized more frequently (100%, or 5/5) than did adenocarcinomas in mixed tumors (34.4%, or 22/64), emphasizing the importance of not lumping these tumors under the classification of malignant mixed tumors.  (+info)

(3/191) Increased expression of ornithine decarboxylase messenger RNA in human esophageal carcinoma.

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthesis of polyamines, which are essential for cell proliferation. The purpose of this study was to evaluate ODC expression in human esophageal cancer at the mRNA level. Sixty-four pairs of primary esophageal cancers and normal esophageal epithelia were examined by reverse transcription-PCR for ODC mRNA expression. The ODC mRNA levels were higher in primary esophageal carcinoma than in adjacent normal esophageal epithelium in 58 (90.6%) of 64 cases. The tumor:normal (T:N) ratio of ODC mRNA expression in esophageal specimens has a significant correlation with tumor-node-metastasis staging (P = 0.043), lymph node metastasis (P = 0.039), vascular vessel invasion (P = 0.035), and histology (P = 0.034) of the tumor. In well- and moderately differentiated squamous cell carcinoma, the patients with a higher T:N ratio showed a significantly poorer prognosis (P = 0.027), and multivariate analysis also confirmed that the T:N ratio has a significant correlation with poor prognosis (P = 0.043). The steady-state of ODC mRNA overexpression in esophageal carcinoma implies that the ODC gene may play an important role in tumorgenesis in squamous epithelium. Furthermore, ODC mRNA expression may be used as a prognostic marker, especially for well- and moderately differentiated squamous cell carcinoma.  (+info)

(4/191) Frequent genetic heterogeneity in the clonal evolution of gynecological carcinosarcoma and its influence on phenotypic diversity.

Carcinosarcomas of the uterus, ovaries, and fallopian tubes are highly aggressive neoplasms with incompletely understood histogenesis. Although recent immunohistochemical, cell culture, and molecular genetic studies all favor these cancers to be monoclonal in origin, the extent of intratumoral genetic heterogeneity in these tumors with divergent histology has not been reported previously. For this study, we microdissected a total of 172 carcinomatous or sarcomatous foci from 17 gynecological carcinosarcomas and analyzed allelic status with 41 microsatellite markers on chromosomal arms 1p, 1q, 3p, 4q, 5q, 6q, 8p, 9p, 10q, 11p, 11q, 13q, 16q, 17p, 17q, 18q, and 22q. With the exception of a single case with microsatellite instability, we found shared allelic losses and retentions among multiple individually dissected foci of each case, strongly supportive of the concept of a monoclonal origin for these neoplasms. In eight of these cases, we also found heterogeneous patterns of allelic loss at limited numbers of chromosomal loci in either the carcinomatous or sarcomatous components of the neoplasms. These heterogeneous patterns of allelic losses were consistent with either genetic progression or genetic diversion occurring during the clonal evolution of these neoplasms. In two cases, we found the specific patterns of genetic progression to be consistent with sarcomatous components of the neoplasms arising from carcinomatous components. We conclude that most of the gynecological carcinosarcomas have a monoclonal origin, and that genetic progression and diversion parallel the development of divergent phenotypes in these tumors. Because phenotypically divergent areas of the tumors share numerous genetic alterations, this divergence most likely occurs relatively late in the evolution of these tumors.  (+info)

(5/191) Pancreatic mucinous cystic neoplasms with sarcomatous stroma: molecular evidence for monoclonal origin with subsequent divergence of the epithelial and sarcomatous components.

Neoplasms with mixed carcinomatous and sarcomatous growth patterns occur in many organs and tissues. The pathogenesis of these cancers is thought to be either the result of two independent neoplastic processes merging to form a single tumor, or a neoplasm of monoclonal origin that develops phenotypic diversity. To address this issue, we characterized molecular alterations in separately microdissected epithelial and sarcomatous areas in three cases of pancreatic mucinous cystic neoplasms with sarcomatous stroma. Using microsatellite markers for six chromosomal loci commonly deleted in infiltrating ductal adenocarcinomas of the pancreas, we found genetic alterations to be virtually identical between the sarcomatous and epithelial components of two of the three neoplasms. In the third neoplasm, we found allelic losses and retentions to be identical at five of the six chromosomal loci, but at a single locus, we noted allelic loss in the neoplastic epithelial component but not the sarcomatous component. The same neoplasms were also analyzed for activating point mutations in codon 12 of the K-ras gene by using mutant-enriched polymerase chain reaction and allele-specific oligonucleotide hybridization. A K-ras mutation was identified in the epithelial component of one of the three neoplasms (the same tumor with an additional allelic loss in the neoplastic epithelial cells), but the sarcomatous component of this tumor was wild-type at codon 12 of K-ras, as were both components of the other two neoplasms. Overall, these results suggest a monoclonal origin with subsequent divergence of the neoplastic epithelial and sarcomatous portions of these neoplasms.  (+info)

(6/191) A so-called carcinosarcoma of the gallbladder in a patient with multiple anomalies--a case report.

The patient was a 65-year-old woman with a chief complaint of right upper quadrant pain. Under the diagnosis of gallbladder tumor, preduodenal portal vein and absence of the pancreatic tail, cholecystectomy was performed. Intraoperative findings resulted in a diagnosis of gallbladder tumor, absence of the pancreatic tail, presence of preduodenal portal vein, and malrotation of the intestine. Histological examination of the resected specimens showed a so-called carcinosarcoma. Carcinosarcoma of the gallbladder is a rare tumor of the hepatobiliary region. The present case differs from previously reported cases in its presentation with multiple anomalies including the presence of preduodenal portal vein. Many cases of preduodenal portal vein in an association with duodenal stenosis in children have been reported, but reports of cases of preduodenal portal vein in adult patients are rarely seen in the literature.  (+info)

(7/191) A case report of sinonasal teratocarcinosarcoma.

A sinonasal teratocarcinosarcoma (SNTCS) is a rare and aggressive malignant neoplasm histologically characterized by the combination of one or more epithelial elements and mesenchymal components. We report a case of a 78-year-old man with SNTCS involving the nasal cavity and paranasal sinuses. He complained of epiphora and exophthalmos with weight loss. Physical and diagnostic images resulted T4N0M0. The tumor was completely and widely resected via a trans-facial approach to perform total maxillectomy with orbital exenteration. The clinical presentation, pathologic features, and clinical course are described with a review of the literature.  (+info)

(8/191) Vascularization of normal and neoplastic tissues grafted to the chick chorioallantois. Role of host and preexisting graft blood vessels.

Adult, embryonic, and tumor tissues were grafted to the chorioallantoic membrane of the chick embryo to determine whether blood vessels originally within implants were reused in the establishment of a new blood supply. Grafts were examined daily by in vivo stereomicroscopy and in histologic sections. Colloidal carbon injections into the host vasculature served to confirm the precise onset of graft circulation; Preexisting tumor blood vessels disintegrated by 24 hours after implantation and revascularization occurred at 3 days by penetration of proliferating host vessels into the tumor tissue. Adult tissues did not revascularize, and the original graft vasculature progressively disintegrated during the 9 days of observation, Most embryonic tissues revascularized in 1 or 2 days by reperfusion of the existing graft vasculature. Anastomosis of host and graft blood vessels seemed to result from connections between newly formed vascular sprouts arising from both vasculatures. This study indicates that only tumor grafts acquire their blood supply solely by formation of new blood vessels from the host microvasculature. By contrast revascularization of normal tissues, when it does occur, is predominately the result of perfusion of the preexisting graft blood vessels.  (+info)