Angiosarcomas express mixed endothelial phenotypes of blood and lymphatic capillaries: podoplanin as a specific marker for lymphatic endothelium. (1/299)

Angiosarcomas apparently derive from blood vessel endothelial cells; however, occasionally their histological features suggest mixed origin from blood and lymphatic endothelia. In the absence of specific positive markers for lymphatic endothelia the precise distinction between these components has not been possible. Here we provide evidence by light and electron microscopic immunohistochemistry that podoplanin, a approximately 38-kd membrane glycoprotein of podocytes, is specifically expressed in the endothelium of lymphatic capillaries, but not in the blood vasculature. In normal skin and kidney, podoplanin colocalized with vascular endothelial growth factor receptor-3, the only other lymphatic marker presently available. Complementary immunostaining of blood vessels was obtained with established endothelial markers (CD31, CD34, factor VIII-related antigen, and Ulex europaeus I lectin) as well as podocalyxin, another podocytic protein that is also localized in endothelia of blood vessels. Podoplanin specifically immunolabeled endothelia of benign tumorous lesions of undisputed lymphatic origin (lymphangiomas, hygromas) and was detected there as a 38-kd protein by immunoblotting. As paradigms of malignant vascular tumors, poorly differentiated (G3) common angiosarcomas (n = 8), epitheloid angiosarcomas (n = 3), and intestinal Kaposi's sarcomas (n = 5) were examined for their podoplanin content in relation to conventional endothelial markers. The relative number of tumor cells expressing podoplanin was estimated and, although the number of cases in this preliminary study was limited to 16, an apparent spectrum of podoplanin expression emerged that can be divided into a low-expression group in which 0-10% of tumor cells contained podoplanin, a moderate-expression group with 30-60% and a high-expression group with 70-100%. Ten of eleven angiosarcomas and all Kaposi's sarcomas showed mixed expression of both lymphatic and blood vascular endothelial phenotypes. By double labeling, most podoplanin-positive tumor cells coexpressed endothelial markers of blood vessels, whereas few tumor cells were positive for individual markers only. From these results we conclude that (1) podoplanin is a selective marker of lymphatic endothelium; (2) G3 angiosarcomas display a quantitative spectrum of podoplanin-expressing tumor cells; (3) in most angiosarcomas, a varying subset of tumor cells coexpresses podoplanin and endothelial markers of blood vessels; and (4) all endothelial cells of Kaposi's sarcomas expressed the lymphatic marker podoplanin.  (+info)

Prognostic value of p53 protein expression for patients with gastric cancer--a multivariate analysis. (2/299)

Mutations in the p53 gene, one of the most common genetic alterations in human cancer, are implicated in tumorigenesis and tumour progression. Although p53 protein expression appears to be correlated to prognosis in patients with malignancy, its prognostic role in gastric cancer has remained controversial. We examined the clinical significance of p53 overexpression in 427 patients with gastric cancer, using multivariate analysis. Tumour sections of gastric cancer tissues from these 427 Japanese patients were stained immunohistochemically with monoclonal antibody PAb1801. The presence of p53 expression was statistically compared with clinicopathological features and post-operative survival, using univariate and multivariate analyses. p53 expression was detected in 38.6% (165 out of 427) of these gastric cancers and immunoreactivity was not observed in normal mucosa adjacent to the tumour. A higher rate of p53 detection was observed among large tumours and in those with a prominent depth of invasion, lymphatic and vascular invasion and lymph node involvement. Prognosis was significantly worse for patients with p53-positive-staining tumours. The 5-year survival rate was 62.5% for patients with p53-negative tumours and 43.3% for those with positive malignancies. p53 expression was a significant prognostic factor for node-positive gastric cancers in subjects undergoing treatment with curative resection, as assessed by Cox regression analysis. Thus, the expression of p53 was closely related to the potential for tumour advance and a poorer post-operative prognosis for patients with gastric cancer.  (+info)

Subclavian artery resection and reconstruction for thoracic inlet cancers. (3/299)

PURPOSE: We previously described an original transcervical approach to resect primary or secondary malignant diseases that invade the thoracic inlet (TI). The purpose of this study was to evaluate the technical aspects and long-term results of the resection and revascularization of the subclavian artery (SA). METHODS: Between 1986 and 1998, 34 patients (mean age, 49 years) underwent en bloc resection of TI cancer that had invaded the SA. The surgical approach was an L-shaped transclavicular cervicotomy in 33 patients. In 14 of these patients, this approach was associated with a posterolateral thoracotomy (n = 10) or a posterior midline approach (n = 4). In one patient, the procedure was achieved with a single posterolateral thoracotomy approach. An end-to-end anastomosis was performed in 16 patients. In one patient, a subclavian-left common carotid artery transposition was performed. In one other patient, an end-to-end anastomosis was performed between the proximal innominate artery and the SA. The right carotid artery was transposed into the SA in an end-to-side fashion. In 16 patients, prosthetic revascularization with a polytetrafluoroethylene graft was performed. Thirty-three patients underwent postoperative radiation therapy. RESULTS: There were no cases of perioperative death, neurologic sequelae, graft infections or occlusions, or limb ischemia. There were two delayed asymptomatic polytetrafluoroethylene graft occlusions at 12 and 31 months. The 5-year patency rate was 85%. During this study, 20 patients died: 18 died of tumor recurrence (5 local and systemic and 13 systemic), one of respiratory failure, and one of an unknown cause at 74 months. The overall 5-year survival rate was 36%, and the 5-year disease-free survival rate was 18%. CONCLUSION: Tumor arterial invasion per se should not be a contraindication to TI cancer resection. This study shows that cancers that invade the SA can be resected through an L-shaped transclavicular cervicotomy, with good results with a concomitant revascularization of the SA.  (+info)

Stereotactic radiosurgery for cavernous sinus cavernous hemangioma--case report. (4/299)

A 40-year-old female presented with cavernous sinus cavernous hemangioma manifesting as left abducens and trigeminal nerve pareses. Magnetic resonance imaging revealed a left cavernous sinus tumor. The tumor was partially removed. Histological examination of the specimen confirmed cavernous hemangioma. Radiosurgery was performed using the gamma knife. The tumor markedly decreased in size after radiosurgery and morbidity was avoided. Cavernous sinus cavernous hemangiomas may be difficult to treat surgically due to intraoperative bleeding and cranial nerve injury. Stereotactic radiosurgery can be used either as an adjunct treatment to craniotomy, or as the primary treatment for small cavernous sinus cavernous hemangioma.  (+info)

Pulmonary artery sarcoma diagnosed using intravascular ultrasound images. (5/299)

Primary and secondary malignant intravascular tumours of the pulmonary artery occur infrequently and the diagnosis is usually delayed as symptoms and findings from conventional examinations are non-specific. The case is presented of a patient with a pulmonary artery sarcoma, probably arising from ribs resected some years previously, in which intravascular ultrasound (IVUS) provided important diagnostic findings.  (+info)

Intravascular lymphomatosis presenting as an ascending cauda equina: conus medullaris syndrome: remission after biweekly CHOP therapy. (6/299)

A 63 year old man developed dysaesthesia in the legs followed by a subacute ascending flaccid paraparesis with sacral sensory and autonomic involvement. Intravascular lymphomatosis (IVL) was favoured by the presence of low grade fever and raised serum C reactive protein, CSF pleocytosis, raised lymphoma markers (serum LDH, soluble IL-2 receptor), and steroid responsiveness. Only muscle, among several organ biopsies, confirmed IVL. A cytogenetic study of the bone marrow showed chromosome 6 monosomy, as previously reported. The monosomy of chromosome 19, which bears the intercellular cell adhesion molecule-1, newly found in this case, may be related to the unique tumour embolisation of IVL. The CHOP regimen (six courses in 12 weeks) using granulocyte colony stimulating factor (G-CSF) led to gradual resolution of myeloradiculopathy and laboratory supported remission lasting for more than 13 months. The biweekly CHOP with G-CSF support may be a choice of chemotherapy in averting rapidly fatal IVL.  (+info)

External jugular vein hemangioma occurring as a lateral neck mass. (7/299)

Hemangioma is an extremely frequent tumor, accounting for 7% of all benign neoplasms. In contrast, hemangioma arising in blood vessels is rare and should be differentiated from other neoplasms of vascular origin, such as hemangioendothelioma, hemangiopericytoma, hemangiosarcoma, and leiomyosarcoma. The case we report has the peculiarity of occurring as a lateral neck mass in which color-coded duplex sonography contributed significantly to diagnosis.  (+info)

Measurement of telomerase activity in dog tumors. (8/299)

Telomeres are specific structures present at the end of liner chromosomes. DNA polymerase can not synthesize the end of liner DNA and, as a result, the telomeres become progressively shortened by successive cell divisions. To overcome the end replication problem, telomerase adds new telomeric sequences to the end of chromosomal DNA. The enzyme activity is undetectable in most normal human adult somatic cells, in which shortening of the telomere is thought to limit the somatic-cell life span. In contrast to normal somatic cells, many human tumors possess telomerase activity. The present study looked at whether telomerase activity might serve as a marker for canine tumors. Telomerase activity was measured using the telomeric repeat amplification protocol assay. Normal dog somatic tissues showed little or no telomerase activity, while normal testis exhibited a high level of telomerase activity. We measured telomerase activity in tumor samples from 45 dogs; 21 mammary gland tumors, 16 tumors developed in the skin and oral cavity, 7 vascular tumors and 1 Sertoli cell tumor. Greater than 95% of the tumor samples contained telomerase activity (3-924 U/2 micrograms protein). The results obtained in this study indicated that telomerase should be a useful diagnostic marker for a variety of dog tumors, and it may serve as a target for antitumor chemotherapy.  (+info)