Sarcoma, Alveolar Soft Part
A variety of rare sarcoma having a reticulated fibrous stroma enclosing groups of sarcoma cells, which resemble epithelial cells and are enclosed in alveoli walled with connective tissue. It is a rare tumor, usually occurring between 15 and 35 years of age. It appears in the muscles of the extremities in adults and most commonly in the head and neck regions of children. Though slow-growing, it commonly metastasizes to the lungs, brain, bones, and lymph nodes. (DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1365)
Soft Tissue Neoplasms
Sarcoma
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
Sarcoma, Clear Cell
A sarcoma of young, often female, adults of the lower extremities and acral regions, intimately bound to tendons as circumscribed but unencapsulated melanin-bearing tumors of neuroectodermal origin. An ultrastructural finding simulates flattened and curved barrel staves, corresponding to the internal structures of premelanosomes. There is a 45-60% mortality in clear cell sarcoma. (Segen, Dictionary of Modern Medicine, 1992)