Frontal mucocele presents as:

Mucocele of the frontal sinus: presents in the superomedial quadrant of the orbit (90%) and displaces the eyeball forward, downward and laterally. The swelling is cystic and nontender; egg-shell crackling may be elicited. Sometimes, it presents as a cystic swelling in the forehead (10%). Patient's complaints are usually mild and may include headache, diplopia and proptosis. Imaging of the frontal sinus usually reveals clouding of the sinus with loss of scalloped outline which is so typical of the normal frontal sinus . Treatment is frontoethmoidectomy with free drainage of frontal sinus into the middle meatus. Ref: Dhingra 7e pg 252