Bone Anatomy
Overview
Bone is the supporting framework of the body. The bone is a hollow structure. The outer layer of the bone consists of a network of fibrous tissues also called matrix, on which calcium salts are deposited. At each end of the bone is a zone of cartilage, a softer form of bone like tissue. Cartilage consists of a fibrous tissue matrix mixed with a gel-like substance. Unlike bone, cartilage does not contain calcium. Cartilage acts as cushion between bones and, together with ligaments and some other tissues, forms the joints between bones.
The outside of the bone is covered with a fibrous tissue called periosteum. The bone contains 2 types of cells. The osteoclast is the cell responsible for forming the bone, and the osteoclast is the cell responsible for dissolving the bone. Bone marrow is the soft tissue inside the hollow bones. The marrow of some bones consists of only fatty tissues. The marrow of other bones is a mixture of flat cells and blood-forming cells. These blood forming cells produce red blood cells, white blood cells, and blood platelets. There are some other cells in the marrow such as plasma cells, fibroblasts, and reticuloendothelial cells.
Primary bone cancers
Most bone cancers are called sarcomas. Sarcomas are cancers that mostly develop from bone, cartilage, muscles, fibrous tissue, fatty tissue, or nerve tissue.
Osteosarcoma – Osteosarcoma is the tumor of the bone itself; it is the most common bone cancer. It is more common in younger people. Males are more likely to be affected.
Chondrosarcoma – This is a cancer of cartilage cells. The risk of this type of cancer rises with age.
Ewing’s tumor – E-wing’s tumor usually develops in bones, and a very small percentage arises in other tissues or organs. Ewing’s tumors of the bone forms in the cavity of the bone. This cancer is primarily seen in children and younger people.
Chordoma – This type of bone cancer usually occurs in the base of the skull and bones of the spine.
Risk factors
Inherited genes
Paget’s disease
Multiple exostoses (overgrowth of bone tissue)
Multiple osteochondromus (benign bone tumors)
Multiple enchondromas (benign cartilage tumors)
Radiation
Bone marrow transplantation
Injuries
Signs and symptoms of bone cancer
Pain – Pain in the affected bone is the most common complaint
Swelling – Swelling in the affected area
Fractures
Generalized symptoms – If the cancer has spread it can cause many symptoms in other organs.
Diagnosis as per modern science
X-Rays
Computed tomography
Magnetic resonance Imaging
Radionuclide bone scan
Positron emission tomography
Biopsy
Staging
Stage I – The tumor is low grade, and is small in size and has not spread.
Stage II – The tumor is high grade and larger, and it has not spread.
Stage III – The tumor is of any grade but it has not spread.
Stage IV – The cancer has spread to the lymph nodes and to distant sites also, other than lung.
