Sphenoid sinus mucocoele presenting with isolated oculomotor nerve palsy

We describe two cases of sphenoid sinus mucocoele. Both presented with isolated oculomotor nerve palsy. Mucocoeles involving only the sphenoid sinus are uncommon. They are probably under-diagnosed as they may be asymptomatic or cause non-specific symptoms. Nasal symptoms occur infrequently but the close relationship of the sphenoid sinus to the orbital apex means that ocular symptoms including cranial nerve palsies are a common presenting feature. Involvement of the third cranial nerve in isolation is rare but has important neurosurgical implications which must be excluded before this symptom is attributed to the sphenoid sinus.