Diagnostic utility of FOSB immunohistochemistry in pseudomyogenic hemangioendothelioma and its histological mimics.

BACKGROUND: Pseudomyogenic hemangioendothelioma (PHE) is an unusual vascular tumor of intermediate malignancy that rarely metastasizes and tends to arise in the lower limbs of young adults and children. Histologically, PHE shows fascicular proliferation of eosinophilic spindle cells and/or epithelioid cells showing "pseudomyogenic" morphology. Immunohistochemically, PHE is usually positive for vimentin, cytokeratin, CD31 and ERG. METHOD: We examined FOSB immunohistochemistry (IHC) in 27 cases consisting of 4 PHE and its histologic mimics including 6 epithelioid hemangioendotheliomas (EHE), 8 angiosarcomas (AS), 4 Kaposi sarcomas (KS) and 5 epithelioid sarcomas (ES). In addition, we performed IHC of CAMTA1 which has recently been established as a useful marker of EHE. We elucidated the diagnostic utility of FOSB IHC in the differential diagnosis of PHE and its histological mimics and also examined the usefulness of FOSB and CAMTA1 IHC combination in the differential diagnosis of the tumors. RESULTS: IHC revealed diffuse and strong FOSB expression in all PHE cases, while the other tumor types demonstrated limited, weak or no FOSB expression. All EHE cases exhibited diffuse and moderate to strong expression of CAMTA1. All tumor types except for EHE showed limited, weak or no CAMTA1 reactivity. CONCLUSIONS: Diffuse and strong FOSB expression was specific for PHE in the current series and FOSB IHC is an effective tool for differentiating between PHE and its histological mimics. Moreover, the combination of FOSB and CAMTA1 IHC is useful for distinguishing PHE from EHE.

Composite hemangioendothelioma and its classification as a low-grade malignancy.

Hemangioendotheliomas are vascular neoplasms occupying a spectrum of biological potential ranging from benign to low-grade malignancy. Composite hemangioendothelioma (CH) is one of the less commonly encountered variants exhibiting a mixture of elements of other hemangioendothelioma subtypes, such as epithelioid, retiform, and spindle cell. Some authors have identified areas histopathologically equivalent to angiosarcoma within CH, raising the question of the true nature of this neoplasm. Although CH recurs locally, there are only 3 reported cases which metastasized. To date, 26 cases (including the present case) have been described in the literature. Herein, we describe a unique case of CH arising in the background of previous radiation therapy and long-standing lymphedema (classically associated with the development of angiosarcoma-Stewart-Treves syndrome) that harbored higher grade areas but behaved as a low-grade malignant neoplasm. This, in conjunction with the many reported cases of CH-harboring angiosarcoma-like areas, and the occasional association with a history of lymphedema, raises the question of whether this variant of hemangioendothelioma may actually be an angiosarcoma that behaves prognostically better than the conventional type. After careful study of the natural disease progression of the current case and review of the literature, we discuss justification for the continued classification of CH as a low-grade malignancy.

Expression of prox1, lymphatic endothelial nuclear transcription factor, in Kaposiform hemangioendothelioma and tufted angioma.

Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA) are rare tumors mainly occurring in early childhood. Our recent results showed that ectopic overexpression of human Prox1 gene, a lymphatic endothelial nuclear transcription factor, promoted an aggressive behavior in 2 murine models of KHE. This dramatic Prox1-induced phenotype prompted us to investigate immunohistochemical staining pattern of Prox1, podoplanin (D2-40), LYVE-1, and Prox1/CD34 as well as double immunofluorescent staining pattern of LYVE-1/CD31 in KHE and TA, compared with other pediatric vascular tumors. For this purpose, we examined 75 vascular lesions: KHE (n=18), TA (n=13), infantile hemangioma (n=13), pyogenic granuloma (n=18), and granulation tissue (n=13). Overall, KHE and TA shared an identical endothelial immunophenotype: the neoplastic spindle cells were Prox1, podoplanin, LYVE-1, CD31, and CD34, whereas endothelial cells within glomeruloid foci were Prox1, podoplanin, LYVE-1, CD31, and CD34. The lesional cells of all infantile hemangiomas and pyogenic granulomas were negative for Prox1 in the presence of positive internal control. These findings provide immunophenotypic evidence to support a preexisting notion that KHE and TA are closely related, if not identical. Overall, our results show, for the first time, that Prox1 is an immunohistochemical biomarker helpful in confirming the diagnosis of KHE/TA and in distinguishing it from infantile hemangioma and pyogenic granuloma.

Intracranial kaposiform hemangioendothelioma: proposal of a new malignant variant.

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of infancy and early childhood that occurs mainly in soft tissue and the retroperitoneum. The pathological characteristics of a KHE are fascicles of spindleshaped endothelial cells and slitlike vascular channels with irregular tumor margins. In spite of benign features such as rare mitoses and a low MIB-1 labeling index, a KHE is categorized as an intermediate malignancy because of local invasiveness into adjacent lymph nodes or organs. Resection is the treatment of choice for this type of tumor and adjuvant medical therapy is prepared for the tumor remnants and the associated Kasabach-Merritt syndrome. In this paper the authors report a case of a KHE without Kasabach-Merritt syndrome arising from the right tentorium cerebelli in a 13-month-old male child. The biological behavior of the tumor, including its pathological traits and clinical course, was malignant in nature. This case may be not only the first intracranial extraaxial KHE, but also the first truly malignant variant. Kaposiform hemangioendothelioma should be considered in the differential diagnosis of intracranial and extraaxial tumors.

[Vascular tumours and malformations, classification, pathology and imaging]. / Tumeurs et malformations vasculaires, classification anatomopathologique et imagerie.

The understanding of vascular anomalies (vascular tumours and vascular malformations) was obscured, for a long time, by confusion and uncertainties in nosology and terminology. The International Society for the Study of Vascular Anomalies (ISSVA) recently adopted a classification scheme, clearly separating vascular tumours (hemangiomas of different types) which result from active cell proliferation, from vascular malformations, which are inborn defects in vascular morphogenesis. These two types of lesions have different clinical behaviour and require different diagnostic and therapeutic strategies. The most frequent vascular tumour is infantile hemangioma. Its clinical aspects and evolution are well-known. New data have been recently obtained concerning the phenotype of tumour cells and its histogenesis. Of the numerous new vascular tumours, which have been recently described, only the congenital hemangiomas, the vascular tumours associated with the Maffucci syndrome and the tumours that may be complicated by a profound thrombocytopenia (Kasabach and Merritt phenomenon) will be considered. Vascular malformations can be classified according to the vessel(s) types they are composed of. A classification table is presented, separating the malformations of vascular trunks from tissular malformations which are more intimately embedded in the surrounding tissues. The different syndromes associated with vascular anomalies take also place in this table. The clinical, imaging and histological aspects of the most frequent malformations (capillary, venous, lymphatic and arteriovenous) are presented. This classification intend to clarify the nosology and terminology of the complex field of vascular tumours and malformation and to offer a common language to the different physicians and specialists contributing, preferably with a interdisciplinary approach, to the diagnosis and treatment of these difficult lesions.

A comparison study of staging systems for bone sarcomas.

A retrospective study of 250 patients treated at one institution was done to evaluate the prognostic significance of the new American Joint Committee on Cancer staging system compared with the Musculoskeletal Tumor Society staging system for patients with sarcomas of bone. Regarding the Musculoskeletal Tumor Society system, there were significant differences in survival among patients with Stage I, Stage II, and Stage III disease. There were no significant differences between patients with Stages I-A and I-B disease, nor between patients with Stages II-A and II-B disease. Similarly, regarding the new American Joint Committee on Cancer staging system, there were significant differences among patients with Stage I, Stage II, and Stage IV disease. No significant differences were seen between patients with Stages I-A and I-B disease, between patients with Stages II-A and II-B disease, nor between patients with Stages IV-A and IV-B disease. A significant advantage in the ability to predict prognosis for one staging system over the other staging system was not shown with the relatively small number of patients in this study.

Vascular tumors and vascular malformations: evidence for an association.

BACKGROUND: The International Society for the Study of Vascular Anomalies classification is an updated biologic classification that distinguishes vascular tumors from vascular malformations on the basis of clinical and histologic characteristics and biologic behavior. OBJECTIVE: We propose that in a minority of cases there is an association between vascular tumors and vascular malformations. METHODS: We retrospectively identified clinical cases in our medical centers and others reported in the medical literature that demonstrate an association between vascular tumors and vascular malformation clinically or histologically. RESULTS: We identified several clinical or histologic settings in which vascular tumors and vascular malformations were associated: (1) coexistence of hemangioma and vascular malformation at the same anatomic site or in close proximity; (2) pyogenic granuloma arising within a vascular malformation; (3) hemangioma associated with developmental vascular anomalies; (4) spindle-cell hemangioendothelioma and venous malformation; (5) kaposiform hemangioendothelioma and lymphatic malformation. CONCLUSION: The biologic classification of vascular birthmarks distinguishing vascular tumors from vascular malformations is clinically useful and forms the framework for our understanding of vascular anomalies. These examples suggest that in a small minority of patients there is an association between vascular tumors and vascular malformations.

Papillary intralymphatic angioendothelioma (PILA): a report of twelve cases of a distinctive vascular tumor with phenotypic features of lymphatic vessels.

Six childhood vascular tumors were designated as "malignant endovascular papillary angioendothelioma" by Dabska in 1969. Since then, a few reports of similar cases were published, often called "Dabska tumors." Twelve similar cases were identified in review of vascular tumors from the authors' institutions. There were five men and seven women, including seven adults. Patient ages ranged from 8 to 59 years (mean, 30 years). The tumors occurred in the dermis or subcutis of the buttocks or thigh (n = 6), thumb or hand (n = 3), abdomen (n = 2), and heel (n = 1). The tumor sizes ranged from 1 to more than 40 cm (mean, 7.0 cm). The unifying feature of all cases was distinctive intravascular growth of well-differentiated endothelial cells presenting as a matchstick columnar configuration, sometimes with a large production of matrix that was positive for collagen type IV. In half the cases, these intravascular proliferations had an associated actin-positive pericytic proliferation. There was minimal cytologic atypia and rare to absent mitotic activity. Two cases had an adjacent lymphangioma, and two additional cases had clusters of lymphatic vessels adjacent to the tumor. All but two of the cases showed varying degrees of stromal or intraluminal lymphocytes. Occasional epithelioid endothelial cells were seen, but no cases had features typical of epithelioid, spindle cell, or retiform hemangioendothelioma. Tumor cells were positive for vimentin, von Willebrand factor, CD31, and focally for CD34 and were negative for keratins, epithelial membrane antigen, S-100 protein, and desmin. Vascular endothelial cell growth factor receptor type 3, a recently introduced marker for lymphatic endothelia, was positive in all eight cases that were studied, supporting a lymphatic phenotype. Follow-up in 8 of the 12 cases showed no evidence of recurrences, metastases, or residual disease during follow-ups ranging from 1 to 17 years (mean, 9 years). Based on the proliferative borderline features and the lymphatic phenotype, we propose to designate these tumors as papillary intralymphatic angioendothelioma. Additional cases with extensive follow-up should be studied to rule out variants with malignant potential.

A new "anonymous" type of haemangioendothelioma.

BACKGROUND: Our report may contribute to a better understanding of the different possible presentations of endothelial tumors. METHODS AND RESULTS: We report a new type of haemangioendotheliomatous tumor of uncertain aggressiveness arisen in a benign haemangioma of the scalp and represented by a proliferation of small- and medium-sized arborescent vessels whose walls were totally replaced by endothelial-like, atypical cells. CONCLUSIONS: The features of our case do not fit those of the many types previously reported in the literature. As regards the name, we prefer to consider this new variety as an anonymous type in order to avoid further confusion on a topic deserving a drastic review.

[Hemangioendotheliomas--evolution of a concept of a heterogeneous group of vascular neoplasms]. / Hämangioendotheliome--Entwicklung eines Konzeptes einer heterogenen Gruppe vaskulärer Tumoren.

The term haemangioendothelioma has been used in the past for a number of vascular lesions, which vary not only by their morphological features, but more importantly, also by their biological behavior. In the recent WHO-classification of mesenchymal tumours haemangioendotheliomas have been defined as vascular tumours of "intermediate" or "borderline" malignancy, and spindle cell haemangioendothelioma (SHE), epithelioid haemangioendothelioma (EHE), and rare malignant endovascular papillary angioendothelioma (Dabska's tumour) were included in this category. To this list might be added the more recently delineated kaposiform (KHE), retiform (RHE), polymorphous (PHE), and composite haemangioendothelioma (CHE). Although very popular, the concept of "borderline" or "intermediate" malignancy encompasses a wide variety of clinical situations, prognosis, and biological behavior. Therefore uncritical use of the term haemangioendothelioma represents a potential source of confusion to patients and oncologists, and it should not be used without further clarification. SHE was originally described as low-grade angiosarcoma, however, the study of large series with expanded follow-up information clarified that these lesions are often multicentric in one anatomic region, whereas true recurrences are rather rare, and systemic metastases and tumour progression do not occur. Therefore redesignation of these lesions as spindle cell haemangioma has been proposed. EHE of skin and soft tissues represents a distinctive vascular neoplasm characterized by nests and cords of epithelioid endothelial tumour cells with characteristic cytoplasmic vacuoles, which are set in a myxohyaline matrix. The reported rates of systemic metastases (20-30%), and tumour related death of patients (13-17%) in EHE, and the occurrence of multicentric EHE argue against the classification of EHE as a low-grade or "borderline" malignant neoplasm; EHE should be better regarded as a clearly malignant vascular tumour (G2). Although it seems that KHE is associated with a high mortality rate, the deaths are almost always related to locally invasive effects or as result of bleeding and consumption coagulopathy. So far no metastasizing case of KHE has been reported, and it seems that the prognosis in KHE is mainly related to size, anatomical site and depth of the lesion. KHE should be classified as a locally aggressive, non-metastasizing vascular tumour. The remaining entities (RHE, Dabska's tumour, PHE, and CHE) are characterized by an infiltrative growth, a high rate of (often repeated) local recurrences, and a definitive risk of metastases. Therefore these lesions fulfil criteria for low-grade malignant vascular neoplasms.

Hemangioendothelioma: a rare vascular tumor in childhood and adolescence.

Most vascular tumors occurring in children are benign. They are recognized by their ability to form angiomatous structures. In some instances, there is no clear-cut line between a benign vascular tumor (or angioma) and a malignant vascular tumor (or angiosarcoma). The hemangioendothelioma is a rare tumor of vascular origin, involving bone or soft tissue, and represents 1% of all vascular neoplasms. Accurate diagnosis is critical in recommending the most appropriate therapy for each patient. The aim of this paper is to give a brief review of the literature of this rare entity, particularly in childhood and adolescence.

Epithelioid hemangioendothelioma of the orbital bones.

PURPOSE: The authors report a case of an epithelioid hemangioendothelioma arising in the orbital bones. A review of the literature related to this rare orbital neoplasm identified eight well-documented cases, one of which occurred in a patient younger than that reported here, but none of which originated in bone. METHODS: A 3 1/2-month-old boy had a left inferior orbital mass that had grown rapidly over a 3-day period. An emergency computed tomography scan showed a large neoplasm with significant bone destruction of the zygoma and maxilla. Initial examination suggested a rhabdomyosarcoma, and a transconjunctival biopsy was performed, which was complicated by significant blood loss. The final pathologic diagnosis was an epithelioid hemangioendothelioma, or grade 2 hemangioendothelioma, of bone origin. No other sites of disease were found on metastatic survey. Subsequent treatment consisted of an en bloc tumor resection sparing the orbital soft tissues and globe. RESULTS: The patient is free of disease and has normal visual fixation and ocular motility 20 months after surgery. CONCLUSION: Epithelioid hemangioendothelioma, a vascular malignancy of endothelial cell origin, very rarely involves the orbit. This case is notable for its early development, rapid growth, bony origin, and epithelioid histology.

[Malignant hemangioendothelioma: its microscopic structure, tissue markers and place among the soft-tissue sarcomas]. / Zlokachestvennaia gemangioéndotelioma: mikroskopicheskaia struktura, tkanevye markery, mesto sredi sarkom miagkikh tkanei.

108 tumors reckoned in the file of the N. N. Petrov Research Institute of Oncology as vascular neoplasms were studied microscopically and histochemically. Malignant hemangioendotheliomas showed formation of vascular structures (a microscopic sign) and expression of specific markers of the endothelium, viz. clotting factor VIII and Ulex Europaeus lectin (immunohistochemical signs). Expression of these signs is determined by degree of tumor differentiation. According to these pathognomonic criteria, only 24 tumors observed at the Institute during 53 years proved hemangioendotheliomas.

Immunohistochemical and cytogenetic studies indicate that malignant angioendotheliomatosis is a primary intravascular (angiotropic) lymphoma.

The authors performed immunohistochemical and cytogenetic studies in a 73-year old man with malignant angioendotheliomatosis. The patient was referred for evaluation of fever of unknown origin, hepatic failure, and neurologic deterioration. Examination of a muscle biopsy revealed numerous, noncohesive atypical mononuclear cells within small vessels. These cells stained positively with a pan-leukocyte marker CD45(PD7/26/16) and with a B-cell marker L26 but negatively with Factor VIII-related antigen, an endothelial cell marker. Peripheral blood obtained before chemotherapy was cultured and analyzed by the G-band method. A new translocation and numerous chromosomal aberrations were identified. The major cell line karyotype was 53,XY, +X, +5q?,-6, +i(6p), +7, -10, +11, -12, +12p-, +12p-, +18, +mar1, +mar2, t(1;3)(p22;p21),3q+,8p+. This is the first cytogenetic study performed in a case of malignant angioendotheliomatosis. Our findings demonstrate that the neoplastic cells in this disorder circulate in the peripheral blood and provide further evidence that malignant angioendotheliomatosis is a diffuse intravascular neoplasm of lymphoid origin. Furthermore, the authors conclude that this malignant lymphoproliferative disorder should be reclassified as a primary intravascular (angiotropic) lymphoma.

[Malignant angioendotheliomatosis].

Malignant angioendotheliomatosis is one of the terms used to describe the appearance of neoplastic cells resembling endothelium within the lumen of small and medium-sized blood vessels, mainly in the cerebral and meningeal vascular beds. A fatal systemic disease with dementia as the leading neurological manifestation may be associated with these pathological findings. Only recently has it become evident that this disease is a unique intravascular form of large cell lymphoma, affecting mainly the cerebral blood vessels but also present in the lumen of many small and medium-sized blood vessels in the systemic circulation.