What are the hematological cancers that affect bone and how do they differ from a sarcoma and a carcinoma?

The hematological cancers that affect bone include myeloma, lymphoma and leukemia. These are cancers that arise from the blood and bone marrow. They can also spread to multiple bones through the bone marrow and create defects or “holes” in the bone risking the bone breaking (fracturing). Sarcomas tend to arise primarily (directly) from bone or soft tissues. They do not arise from bone marrow elements but from other types of cells in the bone or soft tissues. Sarcomas originate from special types of stem cells called mesenchymal stem cells. When a baby is an embryo there are three layers. The middle layer is called the mesoderm and this is where the mesenchymal stem cells originate. Mesoderm makes all the connective tissues and bone in the body like cartilage, bone, fibrous tissue (tendon and ligament type tissue), fat, blood vessels and nerves. Sarcomas can then form tumors that replicate specific tissue types like bone or cartilage. A sarcoma that produces bone is called an osteosarcoma. It is called an osteosarcoma because it produces bone and not because it arises from the bone. A sarcoma that produces cartilage is called a chondrosarcoma. Carcinomas are your typical cancers that everybody hears about: breast cancer, lung cancer, kidney cancer, colon cancer, thyroid cancer, prostate cancer etc. They can spread to the bone and would be considered metastatic bone cancer. Metastatic means to spread to other parts of the body. These cancers develop from the inner layer and outer layer of an embryo called the endoderm and ectoderm.