Distinctive soft tissue tumors of the head and neck.

Among soft tissue tumors as a whole, those in the head and neck region are relatively uncommon, and the proportion of all soft tissue sarcomas that arise in this region is <or=5-10% (although this figure is higher in children). With the exceptions of nasopharyngeal angiofibroma and sinonasal hemangiopericytoma, most mesenchymal lesions are not truly distinctive to this site. This overview focuses on tumors that show a relative predilection for this region, including principally benign fibroblastic/myofibroblastic lesions, nerve sheath tumors, vascular tumors (both benign and malignant), and small round cell sarcomas, especially rhabdomyosarcoma in young patients. Important generalizations to bear in mind include the facts that (1) among spindle cell malignancies in the head and neck of adults, spindle cell carcinoma and melanoma are by far more common than sarcomas; (2) because of anatomic constraints and dramatic clinical presentation, the index of clinical suspicion for malignancy is often high; (3) certain subsets of benign mesenchymal lesions in this anatomic region frequently show pseudosarcomatous morphology; and (4) the ability to define or obtain an adequate surgical resection margin in this region is often very limited, hence issues of local control may supercede the importance of overall biologic/metastatic potential in some cases.