Angiosarcoma Angiosarcomas are malignant tumors that recapitulate many of the functional and morphologic features of normal endothelium. They vary from highly differentiated tumors resembling a hemangioma to anaplastic lesions difficult to distinguish from a poorly differentiated carcinoma or pleomorphic sarcoma.…
Vascular Tumors of Intermediate Malignancy The term hemangioendothelioma is the designation for vascular tumors that have a biologic behavior intermediate between a hemangioma and a conventional angiosarcoma. Tumors included in this group have the ability to recur locally and some…
During the 1930s and 1940s, the diagnosis of adult or pleomorphic rhabdomyosarcoma was increasingly made, and most of the rhabdomyosarcomas reported during this period were of this type. These tumors occurred mainly in the muscles of the lower extremity and…
Striated Muscle Tissue: Development and Structure Skeletal muscle is formed primarily within myotomes, which are arranged in segmental pairs along the spine and make their first appearance in the cephalic region during the third week of intrauterine life. In the…
Leiomyosarcomas account for 5% to 10% of soft tissue sarcomas. They are principally tumors of adults but are far outnumbered even in this age group by more common sarcomas, such as liposarcoma and undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma). Likewise,…
To a large extent, the distribution of benign smooth muscle tumors parallels the distribution of smooth muscle tissue in the body. The tumors tend to be relatively common in the genitourinary and gastrointestinal tracts, less frequent in the skin, and…
Liposarcoma, accounting for 15% to 25% of all sarcomas, is the most common sarcoma of adults. There are several subtypes, which are histologically, biologically, and cytogenetically distinct from one another ( Table 14.1 ). These subtypes range in behavior from…
The significance and multiple functions of fat are not always fully appreciated. Fat serves not only as one of the principal and most readily available sources of energy in the body, but also functions as a barrier for the conservation…
The concept of “malignant fibrous histiocytoma” (MFH) has undergone significant change over six decades, and this term has been supplanted or replaced by undifferentiated pleomorphic sarcoma . The term was introduced in 1963 to refer to a group of soft…
Fibrohistiocytic tumors of intermediate malignancy originally included only dermatofibrosarcoma protuberans and the closely related giant cell fibroblastoma. This category now embraces other lesions, such as plexiform fibrohistiocytic tumor and soft tissue giant cell tumor. Angiomatoid fibrous histiocytoma, formerly considered a…