Gastrointestinal: Adjective referring collectively to the stomach and small and large intestines. The commonly used abbreviation for gastrointestinal is GI. (Outside of medicine, GI can also stand for galvanized iron, general issue or government issue-as in GI Joe).
Before the extracellular matrix is calcified, the tissue is called osteoid (bone-like) tissue. When the concentrations of calcium and phosphate ions rise high enough, they are deposited into the extracellular matrix, and the bone calcifies.
General Information. Osteoid Osteoma is a benign osteoblastic (bone forming) tumor that is usually less than 2cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue.The nidus is surrounded by normal reactive bone. It is usually a single lesion that is very painful.eneral Information. Osteoid Osteoma is a benign osteoblastic (bone forming) tumor that is usually less than 2cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue.