Bone exclusively with red marrow or hematopoietic marrow, but as the child ages the hematopoietic fraction decreases in quantity and the fatty/ yellow fraction called marrow adipose tissue (MAT) increases in quantity. In adults, red marrow is mostly found in the bone marrow of the femur, the ribs, the vertebrae and pelvic bones. Bone is a metabolically active tissue composed of several types of cells. These cells include osteoblasts, which are involved in the creation and mineralization of bone tissue, osteocytes, and osteoclasts, which are involved in the reabsorption of bone tissue. Osteoblasts and osteocytes are derived from osteoprogenitor cells, but
Soft-tissue sarcoma cancer cases each year. This may be because cells in soft tissue, in contrast to tissues that more commonly give rise to malignancies, are not continuously dividing cells. In 2006, about 9,500 new cases were diagnosed in the United States. Soft-tissue sarcomas are more commonly found in older patients (>50 years old), although in children and adolescents under age 20, certain histologies are common (rhabdomyosarcoma, synovial sarcoma). Around 3,300 people were diagnosed with soft-tissue sarcoma in the UK in 2011. "An earlier version of this article was taken from the US National Cancer Center's Cancer Information Service." Soft-tissue sarcoma A