1/65. 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 = antigen (Clic here for more details about this article) |
2/65. Kaposiform hemangioendothelioma of the thymus.Kaposiform hemangioendothelioma is a rare pediatric neoplasm that presents most commonly in the soft tissues. We report the case of a 1-month-old infant who presented with stridor and was found to have a diffusely infiltrating tumor in the thymus that extended into the pericardium and up the carotid sheaths. Histologic examination revealed a vascular tumor infiltrating among the lobules of the lymphocyte-depleted thymus. The lesion had features of both a capillary hemangioma and Kaposi sarcoma. Immunoperoxidase studies on formalin-fixed, paraffin-embedded tissue demonstrated the neoplastic endothelial cells to be positive for vascular markers CD31 and CD34. Antibody to factor viii-related antigen labeled feeding vessels, but failed to stain the lobules of tumor. Although these tumors have been treated in a fashion similar to capillary hemangiomas in the past, it may be important to differentiate Kaposiform hemangioendotheliomas because of their association with kasabach-merritt syndrome and recent success with more aggressive chemotherapy regimens.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/65. Endovascular papillary angioendothelioma (Dabska tumor) of the tongue: report of a case.Endovascular papillary angioendothelioma (EPA), known as Dabska tumor, is a very rare vascular neoplasm that usually occurs in the skin or subcutis of infants and young children. There is no previous report of EPA appearing in the oral cavity. Here, we present an exceptionally rare case of EPA of the tongue in a 67-year-old man. A well-defined, reddish tumor measuring 11 mm x 8 mm x 7 mm existed at the submucosal area of the left tongue margin. Microscopic examination of an excisional biopsy specimen revealed the endothelioid tumor cells showing a papillary growth pattern, such as blood vessel-like structures. Immunohistochemical studies showed positive reactivities for CD31, CD34, alpha-smooth muscle actin, and factor viii-related antigen in most of the tumor cells and CD68 in some tumor cells. Based on these observations, the tumor was diagnosed as an EPA.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/65. Regression of cutaneous intravascular lymphoma with rituximab.Intravascular lymphoma, also known as malignant angioendotheliomatosis or angiotropic lymphoma, is a rare non-Hodgkin lymphoma that is usually fatal. It often presents with cutaneous and/or nervous system involvement, but the disease can involve any organ system. Clinical symptoms result from the occlusion of small vessels by tumor cells and fibrin. We present a case of cutaneous intravascular lymphoma successfully treated with rituximab, a recombinant antibody to CD20 antigen found on B lymphocytes.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/65. hemangioendothelioma of the spleen.Hemangioendotheliomas of the spleen are rare and are considered to be of intermediate/borderline malignancy. We report such a case in a patient who presented with chronic anemia but who otherwise was asymptomatic. The tumor involved half the organ and was solitary and nonencapsulated. Microscopically, it was composed of vascular and stromal elements. Both types of elements showed moderate atypia and rare mitoses. The lining cells stained positively with antibodies to factor viii-related antigen and ulex europaeus lectin. The stromal component showed evidence of myofibroblastic differentiation. One year after splenectomy, all hematologic parameters slowly improved and returned to normal. The clinicopathologic differences between hemangioma, angiosarcoma, and hemangioendothelioma are discussed, and cases that have recently been reported in the literature are reviewed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/65. Retroperitoneal kaposiform hemangioendothelioma with tufted angioma-like features in an infant with kasabach-merritt syndrome.kasabach-merritt syndrome denotes profound thrombocytopenia and coagulopathy in an infant with a vascular tumor. A retroperitoneal vascular tumor with an unusual combination of histopathological features is reported, and compared with vascular lesions described in the reported cases of kasabach-merritt syndrome in the literature. A large retroperitoneal tumor that had expanded through the sigmoid mesocolon into the sigmoid colon wall was resected from an 8-month-old infant with fully developed kasabach-merritt syndrome. Histological examination revealed a combination of venous (cavernous) malformation, kaposiform hemangioendothelioma and tufted angioma-like areas. Cellular tumor components (especially tufted angioma-like parts) infiltrated the wall of the sigmoid colon to the submucosal level. Immunohistochemical staining with antibodies to the ki-67 antigen and proliferating cell nuclear antigen showed a low proliferative activity, whereas the antiapoptotic bcl-2 protein was expressed diffusely in tumor cells. This is the first reported case of a vascular tumor with tufted angioma-like elements found in the retroperitoneum, and the first reported in combination with kaposiform hemangioendothelioma and venous malformation in the same lesion. Considering the immunohistochemical results and overlapping histological features, it may be considered that tufted angioma and kaposiform hemangioendothelioma represent different growth patterns or stages in the development of a single type of hemangioma.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
7/65. Epithelioid and spindle-cell hemangioendothelioma of the spleen. Report of a distinctive splenic vascular neoplasm of childhood.A case of a distinctive vascular neoplasm of the spleen in a 3-year-old boy is described. The tumor was characterized histologically by a biphasic growth pattern, with discrete nodular areas composed of atypical round, epithelioid cells with large nuclei and prominent nucleoli, and areas showing an intricate proliferation of vascular channels lined by elongated spindle cells. Immunohistochemical studies showed cytoplasmic staining of the tumor cells with factor viii-related antigen, ulex europaeus lectin, and vimentin antibodies. Stains for keratin, actin, desmin, lysozyme, and S-100 protein were negative in the tumor cells. Electron microscopy revealed a fairly cohesive population of cells that contained mature and immature cell junctions, basal lamina material, and surface pinocytotic activity consistent with vascular endothelial cells. Five-year follow-up has shown the patient to be alive and free of disease. This case appears to represent a previously unreported primary vascular neoplasm of the spleen showing combined features of epithelioid and spindle-cell hemangioendothelioma. The lesion should be distinguished from other benign and malignant vascular proliferations of the spleen such as Kaposi's sarcoma, angiosarcoma, and the recently described littoral-cell angioma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/65. Angiotropic lymphoma: malignant angioendotheliomatosis.Malignant angioendotheliomatosis is an angiotropic lymphoma that may present with clinical findings suggestive of thrombophlebitis or vasculitis. Examination of a biopsy specimen with special stains for leukocyte common antigen establishes the diagnosis. Although malignant angioendotheliomatosis is usually fatal, early treatment with chemotherapeutic agents is helpful. We review the characteristics and treatment of this uncommon disorder and present an illustrative case.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/65. Angiotropic large cell lymphoma.A 67 year old man developed "status epilepticus" and died with acute respiratory failure. An autopsy and concomitant histological examination, revealed intravascular infiltrate of lymphoid cells throughout the body. Immunohistochemical studies showed intense positive staining for leukocyte common antigen (LCA), L26 and CD20 and negative staining for factor viii- related antigen, and CD5, demonstrated that the neoplastic cells were of B-cell lineage.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
10/65. Malignant thyroid haemangioendothelioma in a non-endemic goitrous region, with immunohistochemical evidence of a vascular origin.A case of malignant haemangioendothelioma of the thyroid is presented in a patient resident in a non-endemic goitrous region of england. The tumour's endothelial origin was confirmed by factor viii-related antigen and ulex europaeus lectin staining.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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