Freiburg Neuropathology Case Conference: Periorbital Bone Lesion Causing Proptosis in a 31-Year-Old Patient

A 31-year-old man presented with a slowly progressing exophthalmus of the left ocular bulb over a period of 5 years. The patient did not report any headache or diplopic images. Ophthalmologic examination showed a normal visual acuity in both eyes and no visual field disturbance. The neurological examination did not reveal any deficits. For the treatment of the left paraorbital mass, a modified lateral orbital decompression (according to Kronlein) was performed. We used three-dimensional image navigation to achieve a safe resection along the altered skull base and to save structures such as foramen ovale, ethmoidal cells medial and below the optic canal, and carotid artery. Resection was performed using high-speed drill along the lateral orbital wall, dorsally up to the foramen ovale with decompression of the trigeminal nerve and along the orbital roof. The bone structure appeared highly vascularized with bony trabeculae. The surface of the lesion had a honeycomb aspect. Central parts of the tumor were rigid and sclerotized, particularly toward the fossa pterygopalatina, where a subtotal resection was achieved. Medial ethmoidal cells were also infiltrated. Dura was not infiltrated, and no CSF leakage occurred. Periorbita was kept closed after achieving a sufficient orbital decompression. Postoperatively, the patient did not present any visual or neurological deterioration. The exophthalmus had slightly improved, and the patient was discharged home on the fifth postoperative day.