Gorham's disease

Gorham's disease is a very rare skeletal condition of unknown cause in which abnormal proliferation of vascular and lymphatic channels within bone leads to progressive bone loss, with the lost bone replaced by angiomas or fibrous tissue. Its exact cause is not established, but researchers believe it involves disrupted bone remodeling in which osteoclasts, the cells that break down bone, become overactive relative to osteoblasts, the cells that build it, possibly driven by elevated levels of interleukin-6 and vascular endothelial growth factor. Commonly affected sites include the shoulder, skull, pelvis, jaw, ribs and spine, and the disease can cause spontaneous fractures or fractures from minor trauma, progressive localized pain and swelling, weakness and visible deformity. When the ribs or chest are involved, patients can develop difficulty breathing, chest pain and fluid accumulation in the chest cavity. The course of the disease is unpredictable, sometimes stabilizing or remitting spontaneously and in severe cases proving fatal.