Members of the DEWS Definition and Classification. Subcommittee developed a contemporary definition of dry eye disease and a three-. part classification system based on etiology, causative mechanisms and disease. severity.
Metaplasia. Definition: Metaplasia is the reversible replacement of one differentiated cell type with another differentiated cell type. Metaplasia causes precursor cells to change their cell fate, and do not change existing differentiated cells.he most common epithelial metaplasia is columnar to squamous (squamous metaplasia), as occurs in the respiratory tract in response to chronic irritation.
Mesenchymal chondrosarcoma is an extremely rare, often aggressive form of cancer. It is a variant type of conventional chondrosarcoma. Conventional chondrosarcoma is a form of bone cancer that arises from cartilage cells. Cartilage is the specialized tissue that serves as a buffer or cushion at joints. Most of the skeleton of an embryo consists of cartilage, which is slowly converted into bone. Approximately two-thirds of cases of mesenchymal chondrosarcoma affect the bones, especially the spine, ribs or jaws.