Angiomatosis with angiokeratoma-like features in children: a light microscopic and immunophenotypic examination of four cases

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Soft-tissue angiomatosis in adulthood: a case in the forearm showing a prominent myxoid adipose tissue component mimicking liposarcoma

Soft-tissue angiomatosis is a rare condition characterized by diffuse proliferation of benign vascular structures, accompanied by mature adipose tissue, which affect a large segment of the body in a contiguous fashion. Most patients present in childhood or adolescence. We report a case of large soft-tissue angiomatosis, located in the left forearm of a 65-year-old man, which showed extensive intramuscular and intermuscular infiltration, and embracement of the radius and the main vascular and neural bundles of the forearm. Due to the deep location, large size, ill-defined limits and non-homogeneous composition with areas suggestive of an adipose component in the radiological examination, the lesion raised the possibility clinically of a liposarcoma. The myxoid adipose tissue component of the lesion, a feature previously undescribed, and the predominance of small, capillary-sized vessels were considered concordant with the clinical diagnosis. This presentation is rare. The features of the lesion made complete surgical excision impossible and amputation of the extremity was considered the best treatment. The main differential diagnoses include infiltrating lipoma, myxolipoma, angiomyxolipoma, angiolipoma, intramuscular angioma, liposarcoma and low-grade myxofibrosarcoma. In conclusion, angiomatosis might simulate liposarcoma, particularly if the mass is large, heterogeneous, myxoid and appears later in life.

Vascular tumors of the skin: A selective review

Cutaneous vascular proliferations are a vast and complex spectrum. Many appear as hamartomas in infancy; others are acquired neoplasms. Some vascular proliferations are hyperplastic in nature, although they mimic hemangiomas, i.e., neoplasms. The vast majority of the vascular lesions are hemangiomas. Between the hemangiomas and frankly angiosarcomas, there is a group of neoplasms that are angiosarcomas, albeit ones of low grade histologically and, probably, biologically. The term "hemangioendothelioma" has been created to encompass these neoplasms. Vascular proliferations are, fundamentally, composed of endothelial cells. Some hemangiomas, however, contain also abundant pericytic, smooth muscle, or interstitial components, or a combination of them. These heterogeneous cellular components are present usually in hemangiomas. Some of the newly described vascular proliferations, however, are difficult to differentiate from some of the angiosarcomas. Others are markers, occasionally, of serious conditions such as Fabry's Disease (angiokeratoma) and POEM's syndrome (glomeruloid hemangioma). Kaposi's sarcoma continues to be an enigma. The demonstration of Herpes virus 8 in this condition raises doubt about its neoplastic nature. The demonstration of endothelial differentiation of its nodular lesions is tenuous and its true nature remains unresolved. While physicians have known about post-mastectomy angiosarcomas from the origin of the radical mastectomy, a new group of unusual vascular proliferations of the mammary skin are being defined. These lesions arise in the setting of breast-conserving surgical treatment with adjuvant radiation therapy. The incubation period is usually 3 to 5 years, in contrast with the 10, or more, in classical cases of post-mastectomy angiosarcoma. These lesions usually are subtle, both clinically and histologically, in contrast with the "classical," dramatic presentation of mammary angiosarcoma. The spectrum of findings ranges from "simple" lymphangiectasia-like vascular proliferations to unequivocal angiosarcomas. The pathogenesis of these lesions remains a mystery. There are very few clues that allow one to separate hemangiomas from angiosarcomas. The presence of heterologous cellular elements and, particularly, well-developed smooth muscle components tends to favor a hemangioma. Similarly, the presence of thrombosis usually supports hemangioma. Nevertheless, there are no unequivocal or reliable individual diagnostic criteria. A thorough knowledge of the different conditions and their differential diagnoses eventually leads to the proper diagnosis in most cases.