Intradiploic epidermoid cyst: diagnosis by ultrasonography and MRI

Epidermoid cysts are well documented. Whenever possible, surgery is always necessary. Intradiploic epidermoid cyst are uncommon, especially in the occipital bone. Ultrasonography (US) may be useful and used instead of radiographs. As demonstrated in intracranial forms, diffusion-weighted MR Imaging (MRI) sequence can be useful for the diagnosis of epidermoid tumors and postoperative assessment of residual tumor. We propose to illustrate the usefulness of US and MRI in depicting an intradiploic epidermoid cyst in a 27 year-old woman.