The neoplasms described in this comprehensive chapter are a heterogeneous group of tumors, having for the most part uncertain histogenesis and no known normal tissue counterpart. Each is characterized by…

In previous editions of this textbook, several entities of uncertain type were placed into either benign or malignant categories. Although these entities still remain an enigma with regard to line…

Benign peripheral nerve sheath tumors differ from other soft tissue tumors in several important respects. Most soft tissue tumors arise from mesodermally derived tissue and display a range of features…

The overwhelming majority of human tumors showing melanocytic differentiation occur in the skin and represent benign melanocytic nevi, their variants, and malignant melanomas. However, a small percentage of tumors showing…

Benign extraosseous cartilaginous lesions are uncommon and usually present as tumorlike masses. In the past, the term soft part chondroma or extraskeletal chondroma was used arbitrarily for small, well-defined, solitary…

The term hemangioma has been used broadly in the past to describe any benign, nonreactive vascular process with an increase in normal or abnormal-appearing vessels or simply abnormally configured vessels….

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…