1/23. Benign vascular neoplasms of the spleen with myoid and angioendotheliomatous features.AIMS: To present the clinical light microscopic and immunophenotypic features of a distinctive vascular neoplasm of the spleen. methods AND RESULTS: Two of the splenic lesions arose in children, and one was found in an adult. They ranged from 19 to 40 mm diameter and histologically were quite similar. Sheets of large epithelioid cells with a spectrum of nuclear configurations ranging from oval and vesicular to twisted and hyperchromatic were noted in each case. Distinct or prominent nucleoli were present in many cells, and occasional cells had nuclear pseudoinclusions. In two cases, bands of basophilic, fibroblast-rich stroma with scattered chronic inflammatory cells were present. The mitotic rate ranged from 0/10 high-power fields (HPF) to 0.5/10 HPF in these epithelioid cells. The vascular nature of these tumours was manifested as a sieve-like array of round, erythrocyte-filled spaces, most with attenuated and cytologically bland lining cells. The polygonal, epithelioid cells exhibited the following phenotype: smooth muscle actin (SMA) , muscle specific actin (MSA) , vimentin , CD31-, CD34-, CD21-, CD8-, CD68- (2/3 cases), S100-, while the lining cells were CD34 , vimentin and SMA-, with variable CD31 and factor viii related antigen expression. Elongated SMA , MSA cell processes were evident in one case, reminiscent of previously characterized myoid elements of the normal spleen. An uneventful follow-up was noted for all three patients. CONCLUSIONS: The histology and immunophenotype set these neoplasms apart from classic hamartomas, haemangiomas and previously characterized (haem)angioendotheliomas of the spleen, and may represent proliferations of myoid elements native to the spleen.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/23. Spindle cell hemangioendothelioma exhibits the ultrastructural features of reactive vascular proliferation rather than of angiosarcoma.A patient with spindle cell hemangioendotheliomas was followed from 1964 to the present time, allowing the authors the opportunity to examine the lesions in the early, mature, and old phases. Organizing thrombi of different stages associated with slit-like vascular proliferation were always observed, whereas cavernous vascular spaces predominated as the lesions became older. Each spindle cell hemangioendothelioma initially developed relatively rapidly and was sometimes painful but then persisted as a silent nodule for decades. Transmission and scanning electron microscopic studies revealed that endothelial cells tended to digitate into the slit-like proliferating channels, became attached to other cells by means of tight junctions, and thus obstructed the channels at sites where thrombi developed repeatedly. The vascular spaces, ranging in nature from slit-like to cavernous, were outlined further by a relatively sparse mantle of ramified or dendritic interstitial cells that corresponded to spindle cells. Most of the cells appeared simply to be fibroblasts, but they developed the features of pericytes when they were close to the endothelial lining of well-developed vascular lumens. Large vascular spaces and phleboliths were surrounded by smooth muscle cells. Approximately 20% of the interstitial cells were dendritic macrophages characterized by phagocytic activity, presence of many lysosomes, and factor xiiia expression. The long and characteristic clinical course, the histologic evidence that thrombosis and its organization was continually occurring within the lesions, and the ultrastructural finding that spindle cell hemangioendotheliomas were composed of different microvascular segments from capillaries to veins, suggest that spindle cell hemangioendotheliomas may develop from a cycle of recanalization after thrombosis that occurs repeatedly because of the unique endothelial growth that was noted. This is in contrast with the previous conception that they were low-grade angiosarcomas.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/23. Intravascular papillary endothelial hyperplasia in the hand of a fencer.A case of intravascular papillary endothelial hyperplasia in the hypothenar eminence of a 23-year-old female fencer is described. Differential diagnosis with other similar benign and malignant lesions was made using histopathology and immunohistochemistry. The possible post-traumatic proliferative histogenesis is discussed. The non-malignant nature of the mass was confirmed after a three year follow-up.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/23. Concurrent infantile hemangioendothelioma and mesenchymal hamartoma in a developmentally arrested liver of an infant requiring hepatic transplantation.A newborn female underwent a surgical resection for a hepatic mass discovered prenatally by ultrasonography, and diagnosed pathologically as a mesenchymal hamartoma. Within 4 months after surgery, multiple cutaneous hemangiomas developed and a multinodular mass was detected in the liver. A liver biopsy showed an infantile hemangioendothelioma with type I features. An orthotopic liver transplant was performed due to the extensive nature of the hepatic involvement and progressive respiratory compromise. Virtually the entire liver was involved by a large infantile hemangioendothelioma. A multicystic mesenchymal hamartoma was also found on the left side. In addition, the uninvolved hepatic parenchyma had features recapitulating the fetal liver. This simultaneous involvement of the liver by a mesenchymal hamartoma and infantile hemangioendothelioma is unique. A review of the literature revealed only one incompletely characterized case with similar findings.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/23. Masson's vegetant intravascular hemangioendothelioma. Fine needle aspiration cytology, histology and immunohistochemistry of a case.Masson's vegetant hemangioendothelioma is a benign intravascular tumor, sometimes confused with such malignant vascular tumors as angiosarcoma, whose clinical appearance is nonspecific and whose diagnosis can only be established through microscopic examination. The fine needle aspiration (FNA) cytologic findings together with the histologic and immunohistochemical findings of such a tumor in a 22-year-old man are presented. Cytologically, the material obtained by FNA consisted of two distinct populations of cells. One type of cell had large nuclei (sometimes displaced towards the periphery), finely granular chromatin, prominent nucleoli and abundant globular cytoplasm. The second type of cell had spindle-shaped or oval nuclei, granular chromatin and scanty eosinophilic cytoplasm. Although these findings may permit the cytologic recognition of this entity, the aspirate in this case was interpreted as showing a vascular mesenchymal tumor of probable malignancy. Histologic examination of the excised tumor, aided by immunoperoxidase studies for factor viii antigen that revealed the endothelial nature of the proliferating cells, established the correct diagnosis.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/23. Angiotropic lymphoma with histologic features of neoplastic angioendotheliomatosis presenting with predominant respiratory and hematologic manifestations. Report of a case and review of the literature [corrected]Neoplastic angioendotheliomatosis (NAE) is a rare fatal disease characterized by widespread intravascular proliferations of neoplastic mononuclear cells. Clinically, dermatologic and bizarre neurologic manifestations usually predominate. The origin of the neoplastic cells remains still undetermined. The authors report a patient with NAE peculiar with respect to the following points: (1) the patient predominantly manifested respiratory symptoms and hematologic findings and lacked cutaneous or neurologic manifestations; and (2) immunohistochemical and molecular genetic studies showed the B-cell nature of the neoplastic cells, although previous cases with predominant respiratory or hematologic manifestations were reported to be of endothelial origin. Despite the rarity, this type of NAE or angiotropic [corrected] lymphoma should be recognized because it is easily confused with other disorders, particularly vasculitis or thrombotic thrombocytopenic purpura.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/23. lung metastasis of malignant epithelioid hemangioendothelioma mimicking a primary intravascular bronchioalveolar tumor. A histologic, ultrastructural, and immunohistochemical study.A 40-year-old woman presented with multiple nodules in both lungs and a small tumoral mass at the level of the left brachial artery. A pathologic diagnosis of pulmonary intravascular bronchioloalveolar tumor (IVBAT) and epithelioid hemangioendothelioma of the limb was established. Morphologic and immunohistochemical studies highly suggest that both tumors are manifestations of the same neoplastic process. In this case a metastatic nature of the IVBAT is suggested. The diagnosis of pulmonary IVBAT should be followed by a search for sclerosing vascular tumors elsewhere. Finally, the results substantiate the vascular origin of the IVBAT.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/23. Cavernous lymphohemangioendothelioma of the right atrium--a case report.The authors report a successful resection of a rare cystic tumor in the right atrium, discovered in an asymptomatic patient with atrial fibrillation. The cystic nature of the tumor was characterized by two-dimensional echocardiogram preoperatively. The site of attachment and movement of the tumor were clearly shown by cine computed tomography preoperatively. The tumor contained numerous endothelium-lined cavernous channels and groups of red blood cells. These features are distinctly different from those of other cystic tumors.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/23. Scintigraphic features of malignant epithelioid hemangioendothelioma.The scintigraphic features of malignant epithelioid hemangioendothelioma of the liver have not been previously documented. In particular, there are no reports on the nature of gallium uptake in these rare tumors. The case reported is a young woman with primary hepatic epithelioid hemangioendothelioma. Metastatic disease in the skull was detected on a Tc-99m MDP bone scan. A Ga-67 study demonstrated that this tumor was not gallium avid.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/23. Epithelioid hemangioendothelioma. Report of a case with immuno-lectinhistochemical and ultrastructural demonstration of its vascular nature.The epithelioid hemangioendothelioma (EHE) is a rare vascular tumour of borderline malignancy, first described as a separate entity in 1982 by Weiss and Enzinger. The abundant cytoplasm of endothelial cells mimiking epithelioid appearances, prominent cytoplasmic vacuolization and barely perceptible lumina even in reticulin stains may result in EHE being mistaken for a signet ring cell carcinoma. In our case, difficulties in differential diagnosis were enhanced by the location of the tumour within an inguinal lymph node. The usefulness of FVIIIR: Ag- and UEA I- histochemistry in ascertaining the endothelial nature of this tumour is demonstrated, in correlation with electron microscopic data. The different reaction sites of these markers are striking and typical: FVIIIR: Ag displays a granular or diffuse cytoplasmic reaction, whereas UEA I provides a linear staining of vacuoles and luminal surfaces.- - - - - - - - - - ranking = 5keywords = nature (Clic here for more details about this article) |
| | Next -> |