Sino-orbital spelunking: stalagmite formation in fibrous dysplasia with dystrophic calcification.

Fibrous dysplasia (FD) involving the mid-face may be associated with cystic and other secondary changes that make diagnosis more difficult. We present a case of FD associated with a remote history of blunt facial trauma and extensive cystic changes involving the medial orbit and sinuses. An endoscopic exploration revealed "stalagmites" along the floor of the cystic cavity that were consistent with dystrophic calcification. This case was unusual given the degree of dystrophic calcification and the presence of sino-orbital stalagmites within the cystic cavity. Radiologic and pathologic features of the stalagmites are characterized.