Cytokeratin expression in epithelioid vascular neoplasms.

Seven epithelioid and eight non-epithelioid vascular tumors were studied by the avidin-biotin-peroxidase method for the presence of endothelial- and epithelial-associated markers, using Ulex europaeus agglutinin-1 (UEA-1) lectin, and antibodies directed against factor VIII-related antigen, (FVIII-RA), vimentin, keratin, carcinoembryonic antigen, and epithelial membrane antigen. The cases included four epithelioid hemangiomas, two epithelioid hemangioendotheliomas (EHE), one epithelioid angiosarcoma (EAS), four common non-epithelioid capillary hemangiomas, and four non-epithelioid angiosarcomas. Staining for FVIII-RA, UEA-1, and vimentin were observed in all cases. The EAS showed staining for keratin in formalin-fixed, paraffin-embedded sections and in frozen sections. Staining for keratin was also observed in frozen sections of one EHE. Both keratin-positive vascular tumors were confirmed with electron microscopy. Carcinoembryonic antigen and epithelial membrane antigen stains were negative in all cases. Our results show that the epithelioid vascular tumors EHE and EAS, in addition to staining for the endothelial markers and vimentin, may also express the epithelial marker keratin. This is important since these tumors may closely resemble carcinomas by routine light microscopy. This study further underscores the importance of using a broad panel of immunohistochemical markers in the diagnostic workup of soft-tissue neoplasms.

Heterogenous expression of endothelial cell markers in infantile hemangioendothelioma. Immunohistochemical study of two solitary cases and one multiple one.

Three cases of infantile hemangioendothelioma were immunohistochemically studied with the use of antibodies against von Willebrand factor (vWF), Ulex europaeus I lectin (UEA I), vimentin, thrombomodulin (TM), and actin, as endothelial cell (EC) markers. Because of a broad variety of histologic features, the growth pattern of the tumor cells was subclassified into the following four subtypes: capillary, sinusoidal, cavernous, and myxomatous parts. The solitary tumor from patients 1 and 2 was composed of these four components, but the multiple tumor in the patient 3 consisted of capillary and sinusoidal parts. Immunohistochemically, vWF and vimentin were dominantly expressed in the ECs of the cavernous and myxomatous parts. UEA I had strongly positive results in all histologic types, except the myxomatous part. Expression of vWF and vimentin in neoplastic EC suggests that functional differentiation of the tumor tissue occurs in the myxomatous and cavernous parts and may be related to the spontaneous regression of the infantile hemangioendothelioma.

Unusual thoracic manifestations of epithelioid hemangioendothelioma.

Intravascular bronchioloalveolar tumors are now recognized as the pulmonary analogue of epithelioid hemangioendotheliomas of the somatic soft tissues. These low-grade endothelial sarcomas have a typical histologic appearance and usually present as bilateral pulmonary nodules in young women. The present report describes four unusual clinical manifestations of the epithelioid hemangioendothelioma: as an anterior mediastinal mass, as diffuse pleural thickening resembling malignant mesothelioma, as a metastatic carcinoma with cancerization of the lymphatics (lymphagitic carcinoma), and as a solitary peripheral calcified nodule. These anomalous clinical presentations correspond to unusual histologic appearances of the tumor at open-lung biopsy, and need to be recognized by both the clinician and the pathologist.

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.

[Protein S-100 in spontaneous soft tissue and peripheral nerve neoplasms in rats]. / Belok S-100 v spontannykh opukholiakh miagkikh tkanei i perifericheskikh nervov krys.

16 spontaneous tumors of the peripheral nerves and 18 spontaneous tumors of mesenchymal origin in BDVI rats were studied by peroxidase-antiperoxidase method using anti-serum (DAKOPATT) against protein S-100. The majority of spontaneous peripheral nerve tumors were of cystic histological structure identical to that of cystic neurinomas induced in rats by ethylnitrosourea and almost all of these tumors were S-100 protein positive. The incidence of spontaneous neurinomas in BDVI rats was in some experiments as high as 5%. All tumors of mesenchymal origin (except one lipoma) were S-100 protein negative: 2 fibromas, 6 fibrosarcomas, 3 malignant fibrous histiocytomas, one rhabdomyosarcoma and one hemangioendothelioma. S-100 protein is found, as in human pathology, useful for distinguishing tumors of schwann cell and mesenchymal origin in rats.

[Epithelioid hemangioendothelioma of the soft tissue. Histology and ultrastructural cytology]. / Das epitheloide Hämangioendotheliom der Weichgewebe. Histologie und ultrastrukturelle Zytologie.

Described in this paper is a case of epithelioid haemangioendothelioma of soft tissue localised in the subcutis of the upper arm of a 47-year old man. The tumour was histologically characterized by cords and nests of plump epithelioid cells separated from each other by typical myxohyaline stroma. Light microscopy revealed also definite vasoformative areas and solid regions with vacuolization which were indicative of so-called intracytoplasmic vacuoles. Atypical nuclei were conspicuous findings. Ultrastructural and immunohistochemical investigations demonstrated the endothelial origin of the lesion. Immunohistochemical investigations also revealed the presence of cellular areas which produced positive response to "factor-VIII-associated antigen". Ultrastructurally the tumour cells exhibited densely packed microfilaments, 8 nm to 10 nm in thickness, and intracytoplasmic vacuoles. The latter were lined and delimited by single membranes, and some of these exhibiting luminal microvilli. The tumour cells exhibited typical pinocytotic vacuoles, with the cords or nests being encircled by thin basal membranes. Typical Weibel-Palade bodies were detectable in some cells. Also recordable from certain cells were intracytoplasmic crystalloid inclusion bodies of a kind never described before in the context of tumour cells of epithelioid haemangioendothelioma. Those inclusions were composed of substructural units of parallel electrodense lines, 19nm to 21nm in periodicity. The nature of epithelioid haemangioendothelioma and its relations with intravascular bronchiolo-alveolar tumours (IVBAT) and myxoid angioblastomatosis of bone were discussed in some detail.

A case of epithelioid hemangioendothelioma of the liver.

A case of epithelioid hemangioendothelioma of the liver is reported. Both immunohistochemical and electron-microscopic examinations revealed the neoplastic cells to share many characteristics with endothelial cells. We discuss and compare this rare tumor, which represents a low-grade sclerosing hemangiosarcoma of the liver, with its pulmonary counterpart, which is known as intravascular bronchioloalveolar tumor (IVBAT).

Steroid hormone receptors in female breast angiosarcomas.

Breast angiosarcoma is an extremely rare neoplasm usually affecting premenopausal women. Previous reports suggest that it is hormone-dependent. A case of primary breast angiosarcoma in a 16-year-old patient is presented in which the presence of estradiol, progesterone, and testosterone receptors was investigated. The histological findings initially revealed a simple angioma, but four months later the histological picture had completely changed, showing an angiosarcoma. Our data indicate a lack of receptors for steroid hormones in this tumor, which argues against the hypothesis presented in the literature.

Distribution of endothelial and basement membrane markers in angiogenic tumors of the nervous system.

The distribution of two endothelial cell markers Factor-VIII-related antigen and Ulex europaeus agglutinin was examined by immunoperoxidase and immunofluorescence techniques in paraffin-embedded specimens representing the three main types of angiogenic neoplasms of the nervous system, hemangioblastoma, hemangioendothelioma and hemangiopericytoma. In addition, the distribution of the basement membrane (BM) marker, laminin, was studied in the same tumors. It was found that Ulex europaeus agglutinin was a more sensitive marker of neoplastic endothelial cells than Factor-VIII-related antigen. Both markers only stained endothelial cells, while the tumor cells of hemangiopericytomas and the stromal cells of hemangioblastomas remained unstained. These findings do not support the view that the stromal cells of hemangioblastomas are derived from endothelial cells. With antiserum to laminin a typical staining pattern could be noticed in each tumor, showing the architectural relationships of the cells very clearly. In all three tumor types laminin was only found in the BM of the vessels, not in the interstices of the neoplastic cells outside vessel lumina. Therefore, the reticulin network previously found between the individual cells of hemangiopericytomas does not correspond to BM. It is concluded that both Ulex europaeus agglutinin and laminin antisera could be valuable new aids for the diagnosis of the three tumor types.

Epithelioid hemangioendothelioma of the central nervous system. Immunohistochemical and ultrastructural observations of a pediatric case.

In 1982, Weiss and Enzinger described a group of soft tissue tumors in adults that they called epithelioid hemangioendothelioma [Cancer 50: 970-981, 1982]. Such tumors have also been found in heart, bone, liver, lung and lymph nodes, and Kepes and Rubinstein described two intracranial examples in adults in 1986 [J. Neuropath. exp. Neurol. 45:319, 1986]. This report documents clinical and pathological features of an epithelioid hemangioendothelioma in the parietal lobe of a 4-year-old boy.

Immunohistochemical and ultrastructural study of early lesions of intravascular bronchioloalveolar tumor with liver involvement.

Autopsy findings including immunohistochemical and ultrastructural study of intravascular bronchioloalveolar tumors (IVBAT) of the lung and liver which were incidentally found in a 68-year-old man were reported. The tumors presented as several, small nodular lesions in bilateral lungs and liver. Immunohistochemical study using the antibody against Factor VIII-related antigen and electron microscopic study suggested endothelial nature of both pulmonary and hepatic lesions. The study by using anti-estradiol antibody revealed the presence of estrogen in the cytoplasm of neoplastic cells, suggesting the possibility of the presence of estrogen receptors in the cells. Although the result is still preliminary, some role of estrogen in the development of IVBAT is suggested. The hepatic lesions have been thought to be metastases from the pulmonary IVBAT but the other possibilities such as primary hepatic or multicentric origin must be considered. Review of the previous reports of IVBAT disclosed several cases which were associated with liver involvement.