Simple fibroma of the orbit I take to be one that springs from the retrobulbar connective tissue, i. e., the orbital fascia within that cavity. Orbital fibroma commonly arises from the periosteum of the orbital walls and less commonly from the sheath of the optic nerve; occasionally from the capsule of the lachrymal gland and rarely from the tendons of the muscles (G. Mizno1).
Marchetti2 reports a case of "peripheral fibroma" which developed on the infraorbital nerve "causing elephantiasis of every part of the skin which was supplied by the compressed nerve." It is altogether probable that this tumor should have been classified as plexiform neuroma.
A few reports have been made of subcutaneous fibroma of the eyelids (Mizno1).
Fibromata of the skin of the eyelids occur in general fibromata (Oliver3).
Heretofore it has not been definitely determined that fibroma is ever derived from retrobulbar connective tissue. Lagrange has