The pathology of head and neck tumors: fibroadipose tissue and skeletal muscle, Part 8.

Benign and malignant tumors originating from mesenchymal cells destined to become lipoblasts and myoblasts affect the head and neck with contrasting frequencies. Lipomas and especially liposarcomas are unusual lesions above the clavicles but when found there behave in a biologic manner identical to that of their counter-parts at other anatomic sites. Myogenic tumors, on the other hand, have a predilection for the head and neck, and for rhabdomyosarcomas this predilection is accentuated in childhood. Combination therapy of rhabdomyosarcomas has obviated radical surgery as a method of treatment, and many sites in the head and neck have benefited prognostically by this treatment. Success, however, is dependent on clinical stage of disease, and rhabdomyosarcomas of the nasopharynx, paranasal sinuses, and middle ear remain more resistant to short-term cures because of the extent of the neoplasm. A review of the clinicopathologic aspects of granular-cell tumors and alveolar soft-part sarcomas is also presented because it has been suggested that these tumors have a myogenous origin.