Clinicopathological features of Kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE), an intermediate tumor of endothelial origin in childhood, is often associated with Kasabach-Merritt phenomenon (KMP). In this study, 22 cases of KHE were immunochemically studied for CD31, CD34, ERG, smooth muscle actin (SMA), D240, GLUT1 and Ki67. The patients (15 males and 7 females) ranged in age from 13 days to 7 years (median, 2 mo). Lesion developed on the extremities/joint (12 cases), chest/abdominal wall (6 cases), head/neck (4 cases), and presented both superficial and deep soft tissue. The superficial change was commonly enlarging cutaneous lesion with ill-defiined red to purple indurated plaque. 15 of the 22 cases (68%) developed KMP, with consumptive thrombocytopenia or bleeding complications. Tumors consisted of infiltrating nodules of fascicles of spindleshaped endothelial cells and slitlike vascular channels with irregular tumor margins. On immunohistochemistry (IHC), endothelial cells were diffusely positive for CD34, CD31 and ERG but negative for GLUT1, and the peripheral area of proliferative capillaries were markedly positive for D240. Adjuvant medical therapy and sclerotherapy were prepared for the tumor and the associated KMP, and then all patients were treated by complete surgical excision. Follow-up information was available in 22 patients (8 to 26 months, mean 15 mo), and indicated that 1 died of multiple organ failure and 21 were alive without residual disease. In conclusion, our results suggest that KHE can occur in the embryonic period, and patients with KMP often have earlier onset time and larger lesional size. KHE patients given with adjuvant corticosteroids and urea injection and complete resection rarely relapse.     

Kaposiform hemangioendothelioma associated with nonimmune fetal hydrops

We describe the case of a 31-week fetus who died in utero with an invasive retroperitoneal kaposiform hemangioendothelioma. This rare vascular neoplasm usually presents as a localized violaceous skin lesion in infants and behaves in a benign fashion; however, kaposiform hemangioendothelioma may present as an invasive neoplasm of the chest or abdominal cavity, where it can lead to the Kasabach-Merritt syndrome, which consists of thrombocytopenia, consumptive coagulopathy, and microangiopathic anemia in association with a vascular anomaly. The case we describe is unique in that the tumor presented in utero and led to intrauterine nonimmune fetal hydrops. Kaposiform hemangioendothelioma has been described in utero; however, to our knowledge, intrauterine fetal death as a direct consequence has not been reported previously in the literature.     

Kaposiform hemangioendothelioma: five patients with cutaneous lesion and long follow-up.

Kaposiform hemangioendothelioma is a rare locally aggressive vascular tumor of the skin, deep soft tissue, and bone in children, characterized by infiltrating nodules and sheets of spindle cells, and unmistakable resemblance to Kaposi's sarcoma. More than 60 patients with such tumor have been reported so far, and while many have died as a result of extensive disease and severe coagulopathy, the long-term biologic behavior of this tumor remains undetermined. We describe five patients with kaposiform hemangioendothelioma and a mean follow-up of 19 years, ranging from 8 to 35 years. This report emphasizes on the importance of cutaneous lesions being the most commonly affected site, but also for its clinical diversity. Early diagnosis is possible even for a small skin lesion, which may be critical for the treatment of a potentially fatal deep-seated extensive tumor. All five patients are well, and three of them with persistent vascular tumor, which has carried two patients from childhood to adult. Although the behavior of this tumor might have been modified by radiation or interferon in three patients, this series indicates that kaposiform hemangioendothelioma is incapable of metastasis, despite a protracted course of many decades with no tendency for spontaneous regression.     

Kaposiform hemangioendothelioma in adult. Report of a case with amianthoid-like fibrosis and angiectases

A rare case of kaposiform hemangioendothelioma in adult is reported. The 11 x 7 x 5 cm tumor was excised from deep subcutis of the abdominal region in 37-year-old man. No signs of Kasabach-Merritt syndrome or lymphangiomatosis were present. Besides typical pattern of kaposiform hemangioendothelioma, following unusual features were found: dilated vessels producing a gross impression of spindle cell hemangioma, areas of amianthoid-like fibrosis, and diffuse immunoreactivity for CD99. The differential diagnosis included mainly spindle cell hemangioma (hemangioendothelioma), hemangiopericytoma-like solitary fibrous tumor, and Kaposi's sarcoma.     

Polymorphous hemangioendothelioma of the neck

Polymorphous hemangioendotheliomas are rare, low-grade borderline malignant vascular tumors of endothelial cell origin. To the best of our knowledge (MEDLINE 1966-2002), there have been nine cases of polymorphous hemangioendothelioma reported in the English literature. Most of the initial patients reported were men, but we present the third case in a woman. Her previous radiation history to the neck makes this report unique. Polymorphous hemangioendothelioma is characterized by the variety of patterns of growth within and between tumors, making histologic recognition of the tumor difficult. Because management remains conservative via wide local excision, the misdiagnosis of this lesion as a malignancy has possible treatment implications. Alternatively, the high propensity for local recurrence underscores the necessity for accurate classification of the neoplasm and close clinical follow-up.     

The hemangioendothelioma of the thyroid

Summary 65 cases of hemangioendothelioma (HE) of the thyroid were accepted as such after control of slides of surgical or autopsy specimen or both. In a few of the more recent cases material could be examined by electron microscope and in some the search for factor VIII-related antigen (FVIIIRAG) was carried out.The demonstration of Weibel-Palade bodies in tumour cells in two cases and the evidence of FVIIIRAG in tumour cells of at least two cases, including primary tumour and distant metastasis, finally show, that the hemangioendothelioma of the thyroid is not simply an anaplastic carcinoma with some peculiar features; at least some of these tumours are true endotheliomas.The proposal that the term hemangioendothelioma be eliminated from the classification of thyroid tumours is therefore unfounded.     

Epithelioid hemangioendothelioma

Summary 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.     

Epithelioid hemangioendothelioma of the inferior vena cava

Epithelioid hemangioendothelioma is a rare endothelial cell-derived tumor of intermediate grade malignancy. It has an unpredictable outcome, independently of the usual histoprognostic criteria. Thirty-three cases with intravascular localisation are described in the literature. We describe a case occurring in a 31-year-old male, which developed an inferior veina cava tumor, with recurrence after incomplete surgical resection and chemotherapy. He was operated on again under extracorporeal circulation and complete surgical resection was then performed. Histologic examination found an intravascular epithelioid hemangioendothelioma developing in the vascular lumen without vascular wall infiltration. This entity represents a challenge not only for the vascular surgeon, but also for the pathologist given its difficult diagnosis.     

Malignant hemangioendothelioma of the superior vena cava

An observation of haemangioendothelioma of v. cava superior found at the necropsy is presented. Clinical manifestations of the v. cava superior syndrome were lacking.     

Infantile hemangioendothelioma of the liver--a case report

A case of type 1 infantile hemangioendothelioma of the liver in a 3 month old male infant who had an abdominal mass incidentally noted at 40 days of age, is described. Grossly, the tumor showed a well circumscribed, pinkish gray and gelatinous mass with areas of central necrosis, multifocal thrombi and hemorrhages, and small cysts. Microscopically, the lesion consisted of numerous vascular channels of various size lined by a single layer of flat or plump endothelial cells. Areas of infarction, thrombosis and calcification, and formation of cavernous hemangiomatous foci were also noted in the lesion. Ultrastructurally, the cells had the characteristics of endothelium, including basal lamina, pinocytic vesicles, and Weibel-Palade bodies. Factor VIII-associated antigen was demonstrated in the tumor cells.     

Primary peritoneal epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma is an uncommon malignant vascular tumor of intermediate grade that occurs in a variety of organs and soft tissues. Diagnosis of epithelioid hemangioendothelioma is often complicated by the rarity of the tumor, and because the tumor shares many morphologic features with other peritoneal neoplasms. This report presents 3 cases of epithelioid hemangioendotheliomas arising as primary tumors of the peritoneum and reviews 7 previously reported cases to establish the demographic, clinical, morphologic, immunohistochemical, and ultrastructural features of this neoplasm. These cases demonstrate that the light microscopic features are very similar to epithelioid hemangioendothelioma arising at more conventional sites, such as the liver, that immunohistochemical analysis provides a reliable approach for confirming or establishing the diagnosis, and that at least one endothelial marker (either CD31, CD34, or factor VIII) should be positive for a definitive diagnosis. This series identifies the characteristics of peritoneal epithelioid hemangioendothelioma that can be reliably used for diagnosis.     

Cytologic features of epithelioid hemangioendothelioma

To determine cytologic features of epithelioid hemangioendothelioma (EHE) that would enable accurate diagnosis, we evaluated fine-needle aspiration biopsy (FNAB) smears from 11 histologically confirmed EHEs. The variably cellular smears comprised dispersed single cells and occasional cell aggregates. Dense stromal fragments were present in association with some tissue fragments. The cells were epithelioid, containing moderate or large amounts of dense cytoplasm. Nuclei exhibited mild pleomorphism, and nuclear grooves were identified in all cases. At least occasional intranuclear pseudoinclusions (INPIs) and intracytoplasmic lumina (ICLs) were present in all cases and in 9 cases (82%), respectively, and rare erythrocytes were seen within ICLs in 5 cases (45%). Mitotic figures were identified in 4 cases (36%). The background was bloody in 6 cases (55%) and contained hemosiderin and/or hemosiderin-laden macrophages in 5 cases (45%). The combination of the following features in FNAB samples should raise strong suspicion for EHE: predominantly dispersed single cells with occasional cohesive cell clusters; epithelioid cytomorphology; dense cytoplasm with well-defined cytoplasmic borders; ICLs (with or without erythrocytes), INPIs, and nuclear grooves. The presence of these features should prompt correlation with clinical, radiologic, and histologic features and immunohistochemical evaluation using vascular markers.     

Phenotypic characterization of the thymus microenvironment study of the human thymus architecture

Phenotypic characterization of the human thymic microenvironment shows the heterogeneity of the epithelial component. Using monoclonal antibody L191, we define here a new antigen common to the flat epithelial cells lining up the thymic capsule and septum, stellate epithelial cells from the subcapsular area and the medulla (M), but lacking on stellate epithelial cells from the inner cortex. Thus, this cell population can be characterized by a series of antigens (TE-4 and P19--shared with HTLV--previously described by B. Haynes et al.) which reflect a common differentiation program--including neuroendocrine specialization--with remarkable differences in the expression of these antigens, occurring during ontogeny and after birth. Another Ab we obtained shows particularities in the cytoskeletal organization of this cell population. Finally the organization of the mesenchymal component was also investigated with a third, anticollagen, antibody. A striking observation we made, using these antibodies, was the relationship between the thymic septum and flat epithelial cells with medullary and Hassal's body (HB) epithelial cells: septae deeply penetrate the medulla so that flat epithelial cells come into direct contact with medullary epithelial cells; in addition, HB are in close contact with the deepest portion of the septae, often separated solely by a single stellate cell. This architectural organization might be related to the differentiation--regeneration process of the thymic epithelium.