Orbital osteoma: three case reports

Osteoma is the most frequent benign tumor of paranasal sinuses. It is generally asymptomatic and usually discovered by chance during radiological imaging. Three cases with orbital extension are reported and discussed.

1st observation: Mrs. M.N. is an 18 years-old caucasian female who presented a stony orbital deformity associated with chronical dacryocystitis. Tomography of the orbit revealed a probable ethmoidal osteoma compressing the lacrimal canals. The management consisted in a surgical excision of the whole tumor by external approach, associated with a dacryocystorhinostomy. The patient's follow-up for the last 12 months was normal. 2nd observation: Miss K.A. is a 16 years-old caucasian female who came to consultation for a swelling of the medial angle of the left eye. Computed tomography images showed a fronto-ethmoidal process displaying a bone density consistent with an osteoma. The tumor was removed through an external ethmoidectomy. The patient was free of symptoms at 6 months follow-up. 3rd observation: Mrs. F. Z. is a 45 years-old patient who presented a 5 years history of right painful exophthalmos. The computed tomography was consistent with a fronto-ethmoidal osteoma with intraorbital extension near the optic nerve. The surgical excision was limited to the intraorbital portion. Postoperative complications included ptosis and diplopia.

Osteomas most commonly affect the fronto-ethmoid sinuses. They rarely show intraorbital extension or cause intracranial complications. They are generally asymptomatic. Symptoms are generally of late onset and are a consequence of tumoral growth and compression of neighbouring organs, as it is the case in our patients. Tumoral exophtalmos is the major ophthalmological sign. The computed tomography is of a great contribution, not only for diagnosis but also for the choice of the surgical approach. The classical surgical technique consists generally in a surgical excision of the osteoma. This surgery may induce ocular or neurochirurgical complications.

Osteomas of the paranasal sinuses are usually asymptomatic. If they become voluminous, they may cause orbital manifestations and serious complications. The rarity of ethmoidal osteoma with orbital growth made our cases interesting to report.