Perineural invasion of the orbit by squamous cell carcinoma.

Two cases of orbital extension by squamous cell carcinoma along the supraorbital nerve are reported. Important clinical aspects of these cases include previous incomplete removal of squamous cell carcinoma of the forehead and altered sensation in the dermatome of the supraorbital nerve. Axial spread of carcinoma along periorbital nerves is an important avenue of local metastasis and should be suspected in all cases of periorbital squamous cell carcinoma.