Figure 2. (A) An 80-year-old man presenting with left-sided facial droop, complete eyelid ptosis, and marked impairment of left ocular motility. (B) A photomicrographic biopsy of the supraorbital branch of the facial nerve revealing PNI of poorly differentiated squamous cell carcinoma (H&E 20x). (C) Positive staining for CK5/6 (20x).
PNI: perineural invasion; CK 5/6: cytokeratin 5/6
