The patient came to the clinic 10-July-2010 complaining of a bony mass at the nuchal protuberance for 9 years. The patient was neurologically free, but complaining of headache with neck pain in the last 6 months and LBP with numbness of the right lower limb  for 1 year.

MRI of the brain done 08-June-2010 showing intraossal eosinophylic granuloma over the confluence sinnuum, which in comparison with the MRI performed 2001 and 2002 became bigger in dimensions. CT-scan performed 08-July-2010 showing the mass destroying the outer and inner bony boundaries.

On examination: The patient is neurologically free.

MRI of the brain with MRV performed 13-July-2010 showing the mass without involvement of the venous structures and has 2 lobulations, more to the right.

In supine position with head in flexion, vertical midline incision was done. The mass was totally removed and drilling of the affected bone was performed.  The dura was seen over the confluence and the bone defect was wide, for what bone cement was used to close the bone defect. The mass was sent for biopsy, it was resembling an epidermoid.

Routine closure of the wound and smooth postoperative recovery.

The patient has benign intraossal mass which was growing several years over the confluence.  It could be an eaosinophylic granuloma or epidermoid. Histological result will clarify the real histology.

When there is large bony defect, it is better to close the defect with bone cement to prevent direct trauma to the sinus.

The final histological result was epidermoid. ( 11-November-2010).