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…

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 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…

Originally viewed as smooth muscle tumors (leiomyoblastomas), it is now known that gastrointestinal stromal tumors ( GISTs ) arise from interstitial cells of Cajal (ICCs) or ICC precursor cells. ICCs…

The concept of fibrohistiocytic neoplasms has been challenged largely because the malignant forms (i.e., malignant fibrous histiocytoma) consistently lack histiocytic features, and because some, when carefully studied, show a subtle…

Although previously grouped together in this textbook, superficial and deep fibromatoses are now discussed separately because of distinct differences in clinical behavior. The superficial fibromatoses are described with the benign…

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…

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…

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…

Immunohistochemistry (IHC) is the use of antibody-based reagents for localization of specific epitopes in tissue sections. Over the past several decades, IHC has become a powerful tool to assist the…