Mucocele of the sphenoid sinus. A benign imitator.

IN recent years, considerable interest has developed in the phenomenon of sphenoid sinus mucocele (Lundgren and Olin, 1961).Important factors are the critical loca- tion of this sinus and the various vital structures which may be involved by an essen- tially benign pathological process originating within its boundaries.We have recently treated a patient in whom the pre-operative diagnosis was that of a malignant parasellar intracranial process, and who has shown good response to simple drainage of the surgically diagnosed mucocele.Case Report A 52-year-old housewife entered the hospital on March 8, 1965, because of headaches and poor vision of 6 months' duration.The patient had apparently been in good health until 6 to 12 months before admission, when severe right-sided headaches and recurrent attacks of vertigo were noted.At the same time, she noted progressive diminution in the vision of both eyes, especially the right.After some attempts at self-medication, the progression of the visual loss caused her to seek medical advice.Her past medical history included a congenital hypoplasia of the left arm and a hysterectomy 15 years previously.She had had frequent attacks of otitis media on the left.Familial and social histories were non-contributory.Examination.-Sheappeared as an obese woman in no distress.Temperature, pulse, respiration, and blood pressure were within normal limits.There were bilateral large central scotomata with marked loss of visual acuity (Fig. 1, opposite).Best corrected visual acuity was 20/200 in the left eye and 2/200 in the right.Severe pallor of the right optic disc and moderate pallor of the left were noted.The left ear showed a profound sensorineural hearing loss.The external auditory canal ended in a blind pouch about 1 cm.deep.Intranasal examination revealed oedematous nasal mucosa, a thickened and markedly deviated nasal septum, and a small amount of thick yellow discharge.Indirect nasopharyngoscopy was negative.On neurological examination, the only additional abnormality noted was the spastic, hypoplastic left arm.Detailed examination of the first, fifth, seventh, ninth, tenth, eleventh, and twelfth cranial nerves gave normal results.X-ray studies and laminograms of the skull revealed destruction of the floor of the sella turcica, and a suggestion of a mass in the sphenoid sinus with displacement of its anterior wall.Clouding of the ethmoid air cells and thinning of the nasal wall of the left orbit were noted.A left carotid arteriogram showed some questionable displacement laterally of the internal carotid artery in the *