A Case Series of Intramuscular Orbital Choristomatous Cysts.

Intramuscular choristomatous cystic lesions within the orbit are rare but may require removal due to their volume effects. The authors describe 2 such cases of intramuscular cysts in adult patients. Both patients presented with symptoms due to local mass effects with swelling, proptosis and diplopia. Imaging confirmed cystic intramuscular masses. Surgical removal involved intraoperative decompression of the cyst to aid dissection with excision of some muscle fibers. Histology confirmed a keratinized stratified squamous lined dermoid cyst within lateral rectus for case 1 and stratified squamous non-keratinized conjunctival epithelium (simple primary conjunctival cyst) within inferior oblique for case 2.