Bone, giant cell tumor of: A tumor of bone characterized by massive destruction of the end (epiphysis) of a long bone. The site most commonly struck by this tumor is the knee — the far end of the femur and the near end of the tibia. The tumor is often coated by new bony growth. It causes pain, restricts movement, and is usually cancerous. Treatment is by surgery, usually followed by chemotherapy.
There is no evidence that the tumor cells themselves are capable of bone destruction; instead, the tumor cells stimulate the formation of cells that function like osteoclasts and resorb bone.
The term “giant cell” reflects the fact that osteoclasts are large multinucleate cells (cells with more than one nucleus) that look gigantic when viewed magnified through a microscope.
Giant cell tumor of bone is also often called osteoclastoma, reflecting the long-held incorrect view that the tumor cells are themselves osteoclasts.
- Bone, heel
Bone, heel: A somewhat rectangular bone at the back of the foot. The words “calcaneus” and “calcium” are related. Medically termed the calcaneus. The calcaneus (from the Latin calcaneum, meaning heel or heel bone) is a bone of the tarsus of the foot which constitutes the heel. In humans, the calcaneus is the largest of […]
- Bone, parietal
Bone, parietal: The main bone on the side of the skull. Although the parietal bone is curved, it is considered a flat bone (as opposed to a tubular bone). The parietal bone is shaped like an irregular quadrangle. It articulates (joins) with the other parietal bone in the midline (top of the head), with the […]
- Bone, sesamoid
Bone, sesamoid: A little bone that is embedded in a joint capsule or tendon; for example, the kneecap (patella).
- Bone, shin
Bone, shin: The larger of the two bones in the lower leg. The shin bone is anatomically known as the tibia. Its smaller companion is the fibula.
- Bone, thigh
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