Osteoporosis Circumscripta Cranii refers to a highly circumscribed (focal) lytic lesion of the skull bone as seen on X-ray in patients with Paget's disease of bones. This focal lesion can be fairly large. This finding is highly specific for Paget's disease of bones.
- Rosen, Clifford J. (1996), Osteoporosis: diagnostic and therapeutic principles, Humana Press, p. 11, ISBN 978-0-89603-374-0