Frozen Section Histoanatomy of the Peritarsal Eyelid.

BACKGROUND:Mohs surgery of eyelid skin cancers requires detailed knowledge of anatomy for precise surgery and accurate evaluation of histology. OBJECTIVE:To review the histology of the peritarsal eyelid using frozen sections as encountered intraoperatively by Mohs surgeons. METHODS:The authors review the literature describing the anatomy and histology of the peritarsal eyelid from the lens of a Mohs surgeon. Histology from select Mohs cases is used to frame the discussion of the microanatomy of this region. RESULTS:The peritarsal eyelids contain a unique mixture of skin, muscle, tarsus, glandular tissue, and conjunctiva. The histologic appearance of many of these structures differs from skin found outside of this anatomic region. Tumors of the eyelid and periocular region may mimic normal histologic structures found within the peritarsal eyelid. CONCLUSION:The peritarsal eyelids have unique anatomy and associated histologic structures. Knowledge of the detailed histoanatomy is required for confident execution of Mohs surgery in this anatomic region.