Basal cell carcinoma, the most common eyelid malignancy, accounts for approximately 90%–95% of malignant eyelid tumors. A prospective series of 1295 patients found that basal cell carcinomas are most often located on the medial canthus (48.3%), lower eyelid (47.5%), and upper eyelid (3.9%). Basal cell carcinomas can have many different clinical manifestations in the eyelid (Fig 10-46).
Patients at highest risk for basal cell carcinoma are fair-skinned, blue-eyed, red-haired or blond, and middle-aged and elderly persons with English, Irish, Scottish, or Scandinavian ancestry. A history of prolonged sun exposure during the first 2 decades of life and a history of cigarette smoking also increase the risk of basal cell carcinoma. Patients with prior basal cell carcinomas have a higher probability of developing additional skin cancers.
Basal cell carcinoma is being seen with increasing frequency in younger patients, and discovery of malignant eyelid lesions in these patients or those with a positive family history should prompt inquiry into possible systemic associations such as basal cell nevus syndrome or xeroderma pigmentosum:
Basal cell carcinoma may simulate chronic inflammation of the eyelid margin and is frequently associated with madarosis. Multicentric or superficial basal cell carcinoma may be mistaken for chronic blepharitis and can silently extend along the eyelid margin.
A biopsy is necessary to confirm any clinical suspicion of basal cell carcinoma (Fig 10-50). The most accurate diagnosis is facilitated by obtaining an incisional biopsy specimen that
is representative of the clinically evident lesion
is large enough for histologic processing
is not excessively traumatized, cauterized, or crushed
contains normal tissue at the margin to show the transitional area
The biopsy site should be first photographed, as the site often heals so well that the original location can be difficult to find for subsequent tumor removal.
An incisional biopsy, in which only a portion of the lesion is biopsied, can be used as a confirmatory office procedure if the suspected malignant tumor involves the eyelid margin or medial canthus or is especially large.
Figure 10-50 Techniques of eyelid biopsy. A, Incisional. B, Lateral canthal. C, Excisional. D, Full-thickness margin wedge resection. E, Shave.
(Illustration by Cat N. Burkat, MD.)
An excisional biopsy is reasonable when lesions are small and do not involve the eyelid margin or when eyelid margin lesions are away from the lateral canthus or lacrimal punctum. However, histologic monitoring of tumor borders to ensure complete excision is critical. The borders of any excisional biopsy should be marked in case the excision is incomplete and further resection is necessary. Excisional biopsies should be oriented vertically so that closure avoids vertical traction on the eyelid that could lead to eyelid retraction or ectropion. If the margins of the excised portion are positive for residual tumor cells, the involved eyelid area should be excised again, with surgical monitoring of the margins by Mohs micrographic technique or frozen section technique.
Surgery is the treatment of choice for all basal cell carcinomas of the eyelid. Surgical excision affords the advantages of complete tumor removal with histologic control of the margins. The recurrence rate is lower with excision than with any other treatment modality. Surgical excision also offers superior cosmetic results in most cases.
When basal cell carcinomas involve the medial canthal area, the lacrimal drainage system may be excised in order to completely eradicate the tumor. If the lacrimal drainage system has been removed, reconstruction of the lacrimal outflow system is not undertaken until it is established that the patient is tumor free.
Incidence of orbital invasion of basal cell carcinoma is 2%–4% and occurs most commonly in cases that have been inadequately treated, in clinically neglected tumors, in morpheaform tumors, or in tumors with perineural spread. Orbital exenteration may be required in such cases. Retrospective studies show that the mortality rate from ocular adnexal basal cell carcinoma is 3%. The vast majority of patients who have died from basal cell carcinoma had disease that started in the canthal area, had undergone prior radiation therapy, or had clinically neglected tumors.
Histologic examination of the margins of an excised malignant tumor should confirm complete tumor removal. During surgery, frozen section techniques can be employed in which the clinically apparent tumor, along with 1–2 mm margins, is excised, oriented on a detailed drawing, and sent to pathology for immediate frozen section evaluation.
Reconstruction is undertaken when all margins are found to be free of tumor. Some tumors have subcutaneous extensions that are not recognized preoperatively. Consequently, the surgeon must always be prepared to do a much larger reconstruction than originally anticipated from the clinical appearance of the tumor.
To facilitate complete removal of recurrent, deeply infiltrated, or morpheaform tumors and tumors in the medial canthus, dermatologists with special training often use Mohs micrographic surgery. Tissue may be removed in thin layers that allow 3-dimensional mapping of the tumor excision. Mohs micrographic tumor resection is most commonly used for excision of squamous cell and morpheaform basal cell carcinoma.
Micrographic excision preserves the maximal amount of healthy tissue while providing the best assurance of complete cancer removal. Preoperative planning involving both the micrographic surgeon and the oculoplastic surgeon enables the most efficient patient care. In some cases, micrographic excision may allow the globe to be retained, whereas conventional surgical techniques might indicate the need for exenteration. However, a limitation of Mohs micrographic surgery is in identifying margins of the tumor if it has invaded orbital fat.
Following Mohs tumor resection, the eyelid should be reconstructed by the ophthalmologist. (Reconstruction techniques are reviewed in Chapter 11.) Although urgent reconstruction is not critical, the procedure should be performed expeditiously. Early surgery affords maximum globe protection and fresh eyelid tissue margins for optimal reconstruction. If immediate reconstruction is not possible, the cornea should be protected by patching or temporarily suturing the remaining eyelid closed over the globe. If defects are small, spontaneous granulation may be a treatment alternative.
The recurrence rate following cryotherapy is higher than that following surgical therapy for well-circumscribed nodular lesions. When cryotherapy is used to treat more diffuse sclerosing lesions, the recurrence rate is unacceptably high. In addition, histologic margins cannot be evaluated with cryotherapy. Consequently, this treatment modality is avoided for canthal lesions, recurrent lesions, lesions greater than 1 cm in diameter, and morpheaform lesions. Furthermore, cryotherapy may cause depigmentation and tissue atrophy, resulting in suboptimal final cosmesis. Therefore, cryotherapy for eyelid basal cell carcinoma is generally reserved for patients who are poor surgical candidates.
Radiation therapy should also be considered only as a palliative treatment that should generally be avoided for periorbital lesions. In particular, it should not be used for canthal lesions because of the risk of orbital recurrence. As with cryotherapy, histologic margins cannot be evaluated, and the recurrence rate is higher after radiation treatment than after surgical treatment. Moreover, recurrence after radiation is more difficult to detect, occurs at a longer interval after initial treatment, and is more challenging to manage surgically because of the altered healing of previously irradiated tissues.
Complications of radiation therapy include cicatricial changes in the eyelids, lacrimal drainage scarring with obstruction, keratitis sicca, and radiation-induced malignancy. Radiation may also cause injury to the globe if it is not shielded during treatment. See also BCSC Section 4, Ophthalmic Pathology and Intraocular Tumors.
Oral vismodegib or sonidegib may be useful treatments for advanced orbital infiltrative basal cell carcinoma that is not amenable to surgical resection or radiation. Initial studies show that these drugs are well tolerated and effective, although patients need to be carefully monitored for squamous cell carcinomas at uninvolved sites. Side effects include muscle spasm, alopecia, change in taste, and diarrhea.
Demirci H, Worden F, Nelson CC, Elner VM, Kahana A. Efficacy of vismodegib (Erivedge) for basal cell carcinoma involving the orbit and periocular area. Ophthalmic Plast Reconstr Surg. 2015;31(6):463–466.