The pathological diagnosis of CAB should be made in association with typical radiographic findings and clinical features; it has been found that of all the bones that appear to be involved, the rib provides the highest diagnostic yield . Macroscopically, the lesion may resemble a typical bone cyst. The microscopic appearance is of dilated, cavernous vascular channels surrounded by a single layer of flattened endothelial cells, which may be of blood vessel or lymphatic origin, as indicated by their contents. This distinction can sometimes be difficult to make, especially if the cystic spaces are filled with fluid. Patients with CAB have been described who have lymphangiomas at one site and typical hemangiomas at others. buy diabetes drugs
In addition to showing the replacement of the marrow space by vascular channels, bone biopsies in the present patient showed large focal areas with active osteoclastic bone resorption. These areas were located directly adjacent to the vascular intramedullary stroma, in places resembling the features of osteitis fibrosa cystica.