Myoid angioendothelioma of the spleen mimicking metastatic disease in a patient with rectal cancer: a radiologic-pathologic correlation

Myoid angioendothelioma of the spleen is an uncommon, benign vascular tumor that is morphologically characterized by a composite of vascular spaces and stromal cells with myoid feature. Herein, we report a case of the myoid angioendothelioma of the spleen, concurrent with rectal adenocarcinoma. A 41-year-old woman presented with hematochezia for several weeks. Grossly, the rectal mass was a 2.5 × 2-cm ulcerative fungating lesion. The splenic mass was a 2.2 × 2-cm well-circumscribed lesion. Microscopically, the rectal mass was a well-differentiated adenocarcinoma that invaded into the pericolic adipose tissue. The splenic mass was composed of slit-like vascular spaces and fascicles of elongated stromal cells. Vascular endothelial cells were immunopositive for CD31, factor VIII–related antigen, and CD34 but negative for CD8. Stromal cells were immunopositive for smooth muscle actin but negative for desmin.     

Endovascular papillary angioendothelioma

One case of a rare vascular tumor which occurs mainly in the childhood is presented. The tumor has a tendency to recurrence and metastases into the regional lymph nodes in spite of a relatively mature structure.     

Myoid hamartomas of the breast

Tumors containing smooth muscle are rare in the breast. A myoepithelial origin for the myoid component of such lesions was postulated in previous reports. Myoepithelial hyperplasia has long been recognized as a common component of some breast lesions, including sclerosing adenosis, papillomas, and fibroadenomas. Three breast tumors composed of variable admixtures of adipose tissue, fibrous tissue, and smooth muscle are described. The authors postulate that the myoid component of two of the three lesions may have arisen in a milieu of myoepithelial hyperplasia. The origin of the myoid component in the third case is not clearly defined.     

Endovascular papillary angioendothelioma (Dabska tumor)

The histological diagnosis of endovascular papillary angioendothelioma (EPA) (Dabska tumor) is controversial although the tumor is included in the World Health Organization classification. Papillary endothelial proliferation with a central hyaline core is one of the most characteristic features of EPA; however, this type of proliferation has been observed in other vascular tumors, such as angiosarcoma, retiform hemangioendothelloma and glomeruloid hemangioma. Several vascular tumors have EPA-like foci and EPA is not well defined generally. Endovascular papillary angioendothelioma may not be a distinct entity and may well include a heterogeneous group of lesions.     

Malignant endovascular papillary angioendothelioma. Cutaneous borderline tumor

Malignant endovascular papillary angioendothelioma, a rare but distinctive vascular tumor of childhood, was first described in 1969. It was termed malignant because of its mitotic activity, areas of necrosis, and demonstrated ability to metastasize to regional lymph nodes. Despite these features it had a uniformly good prognosis. We report an example of this lesion in a 6-year-old boy that does not show malignant histologic features. Based on its good long-term prognosis and variable histologic features, this lesion is better classified as a borderline vascular tumor.     

Myoid Cell Antibody in Rheumatic Fever

Cardiac myofiber band antibodies, cross-reactive with skeletal muscle cross-striations and with the cytoplasm of thymic myoid cells, were demonstrated in sera from patients with acute rheumatlc fever and uncomplicated group A streptococcal infections.     

Myoid Cell Antibody in Rheumatic Fever

Cardiac myofiber band antibodies, cross-reactive with skeletal muscle cross-striations and with the cytoplasm of thymic myoid cells, were demonstrated in sera from patients with acute rheumatlc fever and uncomplicated group A streptococcal infections.     

Endovascular papillary angioendothelioma in an elderly female

Endovascular papillary angioendothelioma (EPA) is a rare vascular tumor of low grade malignancy, encountered primarily in children. However some cases have also been reported in adults. A sixty year old female with EPA is described here. She presented with a swelling in the neck. Total surgical excision was performed. Histomorphology revealed anastomosing lymphatic channels showing intraluminal papillary fronds with hyaline vascular cores and hobnailing of endothelial cells. A diagnosis of EPA was made based on this picture. This tumor is recurrent and nodal metastasis has been reported in some cases.     

Fine needle aspiration cytology of malignant endovascular papillary angioendothelioma

Here we described a rare case of malignant endovascular papillary angioendothelioma (Dabska tumor) in an adult female. On fine needle aspiration, the smear showed many small clusters of tumor cells with rosettoid arrangement along with papillary fragments with fibrovascular core and hobnail like arrangement of the cells. Histopathological examination revealed a vascular tumor in the form of papillary projection into the vascular lumina, lined by atypical endothelial cells.     

Myoid and epithelial cell differentiation in myasthenic thymuses.

This study demonstrates that the stromal thymus elements of postcapillary venules are the source of desmin-positive mesenchyme from which both myoid and epithelial cells arise. The double staining revealed various degrees of desmin and keratin positivity in the same kind of cells in the medulla as well as in Hassall's corpuscles. Hassall's corpuscles seem to arise from several kinds of cells of which one appears to be monocytogenic and expressed S100 protein.     

Myoid cell differentiation in true thymic hyperplasia and lymphoid hyperplasia

Four cases of thymic hyperplasia (TH) and/or lymphoid hyperplasia (LH) were investigated immunohistochemically for evidence of myoid cell (MC) and epithelial cell (EC) differentiation using antibodies to myoglobin, desmin, and cytokeratin. Although MCs were identified in all the cases, the most impressive perifollicular proliferation of ECs and MCs was seen in the hyperthyroid patient with TH/LH, suggesting that these cells have a role in immune function. The unusual combination of LH and TH in this patient demonstrates that exceptional cases can show overlapping features of what are otherwise considered to be separate thymic lesions. The observations that MCs occur in close proximity to ECs and ECs are depleted along with MCs in myasthenia gravis provide strong evidence supporting closely related histogeneses for ECs and MCs within the thymus.     

Endovascular papillary angioendothelioma (Dabska tumor) in an elderly woman

A patient with endovascular papillary angioendothelioma with a low grade of malignancy showing papillary proliferation of endothellold cells Is presented. The patient, an 83-year-old woman, underwent resection of a tumor of the neck. At operation a 9×7 cm cystic tumor containing yellow transparent liquid with clots was found In the subcutaneous tissue. Histological studies showed endotheliold cells with spindle-shaped nuclei proliferated in layers around the fibrovascular cores, which showed the characteristic appearance of papillary proliferation. These cells were Immunohlstochemlcally positive for CD31, CD34 and factor VIII-related antigen. Based on these observations, the tumor was considered to be an endovascular papillary angioendothelioma (Dabska tumor). Dabska tumor Is a vascular tumor with a low grade of malignancy and usually occurs in infants and young children. About 13 cases of Dabska tumor have been reported. The occurrence of a Dabska tumor In an aged patient is considered to be rare.     

Myoid hamartomas of the breast: report of 3 cases and review of the literature

Hamartomas were first described by Albrecht in 1904, who defined them as tumor-like malformations in which there was abnormal blending of the normal components of an organ. The myoid hamartoma is a rare benign lesion of the breast and has an uncertain origin, possibly in the walls of the blood vessels, muscularis mammillae of the areolae, and mainly in myoepithelium. We report 3 cases of myoid hamartomas of the breast, with the clinical, radiologic, and histopathological findings, and review the literature. The 3 lesions showed normal breast ducts and lobules, entrapped by a muscular stroma and some foci of mature adipose tissue. The muscular origin of part of the stroma was confirmed by strong reactiveness with smooth-muscle actin.