M85.0: Fibrous dysplasia (monostotic)

Fibrous dysplasia (monostotic) is a rare, noncancerous bone condition where normal bone is replaced by a fibrous-like tissue leading to areas of the bone becoming weak and deformed. While it typically develops during childhood or adolescence, symptoms can sometimes only become apparent in adulthood. This condition usually appears in one bone, hence the name 'monostotic'. Common sites affected include the long bones, skull, ribs, and pelvis. Symptoms may include bone pain, fractures, bony deformities, or uneven growth. In some cases, there may be no symptoms at all and the condition is found incidentally on X-rays for unrelated issues. The exact cause of Fibrous dysplasia (monostotic) remains unknown, but it is believed that the condition results from a modest mutation that happens after conception. It's important to note that this condition isn't considered hereditary, meaning it isn't passed from parents to children.