Presentation
Young female with painless proptosis.
Patient Data
MR shows well defined lobulated homogeneous intraosseous cystic lesion in the lateral wall of the right orbit. The lesion is hypointense on T1WI and hyperintense on T2WI. The lesion shows restricted diffusion. There is an intraorbital extraconal extension with lateral rectus muscle compression and causing the proptosis. The lesion also extended to the temporalis fossa laterally. No intracranial extension. No enhancement after IV contrast administration (Postcontrast images not shown due to movement artifacts and suboptimal quality).
Findings most suggestive with orbital intradiploic epidermoid cyst.
CT shows well-demarcated hypodense lesion with bone destructions and sclerotic borders. The lesion mainly located at the lateral orbital wall, extend into the greater wing of the sphenoid bone, zygomatic bone, intraorbital extraconal space, and temporalis fossa.
Case Discussion
Dermoid and epidermoid cysts are the most common orbital tumors.
Intradiploc epidermoid cyst primarily located in the bony orbit and secondary extending to the orbit and causing proptosis is a very uncommon case.