Abstract
The eyelid protects the eye from environmental insults and assists in keeping the cornea moist. At only 0.6 mm thick, the periorbital skin is one of the thinnest cutaneous surfaces of the body. Mohs micrographic surgery (MMS) offers advantages over other resection techniques for this area because it attempts to conserve tissue and preserve function. A thorough understanding of the anatomy of this area is paramount to avoid permanently damaging vital structures. The patient’s eye must be protected at all times.
Basal cell carcinoma (BCC) is the most common malignancy in the periorbital region and accounts for 90–95% of all periorbital malignancies. Although BCCs are not likely to metastasize, they can locally grow to destroy the eye, orbit, nose, and sinuses. A number of histologic subtypes of periorbital BCCs are associated with a higher likelihood of recurrence including: multicentric, desmoplastic, basosquamous, keratotic, morpheaform, and micronodular. Dr. Mohs published the largest series using Mohs micrographic surgery (MMS) to treat periorbital BCC, and out of 1,124 cases of primary BCC and 290 recurrent BCCs, the 5-year cure rates were 99.4% and 92.4%, respectively!
The second most common periorbital malignancy is squamous cell carcinoma (SCC), accounting for approximately 5–10% of all periorbital malignancies. Similar to BCC, SCC presents more commonly on the lower eyelid but not to the same extent as BCC. Unlike periorbital BCC, the metastatic rates of periorbital SCC have been reported to be as high as 21%. Unfortunately, SCC of the eyelid is much more likely to recur and metastasize when compared to other anatomical locations.