sections, thereby increasing the likelihood of finding tumor. To avoid the possibility of a narrow Mohs margin, excising an extra layer for paraffin sections may be judicious.

26.4.4Clinicopathologic Features of Poor Outcomes

Rao et al. [4] listed the clinicopathologic features of a poor prognosis and metastasis. In ascending order of metastasis, these are (1) duration of symptoms of more than 6 months, (2) tumor larger than 10 mm, (3) multicentric origin, (4) highly infiltrative pattern, (5) upper and lower lid involvement, (6) pagetoid invasion, (7) orbital invasion, and (8) vascular and lymphatic invasion. In general, upper lid SC metastasizes to the preauricular and parotid nodes. Lower lid SC metastasizes usually to the submandibular and cervical neck nodes [19]. Historically, regional node metastasis occurred in about 30% of the cases [19]. Standard therapy is parotidectomy, neck dissection, and radiation [17, 41].

Summary: Treatment

•A diagnostic biopsy should be considered for any lesion on eyelids that is suspicious for sebaceous carcinoma. Scouting biopsy might be needed for multicentric lesions.

•Traditional wide local excision is the main method that oculoplastic surgeons use to excise sebaceous carcinoma. Exenteration might be needed for patients with orbital spread.

•Mohs micrographic surgery is an efficient method to remove sebaceous carcinoma using frozen sections. Oil Red O stain that highlights lipid on frozen sections is useful.

•Mohs micrographic surgery can be supplemented with paraffin sections especially for assessment of epithelial margins.

26.5Treatment

The following paragraphs focus on surgical management. Other methods of management include radiation [42, 46], cryosurgery [42], mitomycin C [47].

26.5.1 Biopsy Procedure

The most common presentation for SC is a sty or chalazion. When the patient is examined, there is usually moderate swelling with or without discomfort. An incisional biopsy is a relatively simple procedure that provides drainage, and promotes healing. A partialthickness biopsy is typically performed. A full-thickness skin and conjunctiva biopsy is indicated where a previous incisional biopsy was inconclusive. When there is severely inflamed tissue, several additional scouting biopsies are taken. For advanced tumors that have “skip” areas or have multiple foci that may be missed with a single biopsy, therefore, several biopsies may be necessary [42]. One should be wary if a biopsy of the conjunctiva, fornix, and caruncle returns a diagnosis of SCC in situ [29, 33].

26.5.2 Conjunctiva Mapped Biopsies

Extension of the tumor to the fornix may require conjunctival map scouting biopsies that are excised with scissors, submitted to ocular pathology, and sectioned vertically. Ideally, between 12 and 16 biopsies are performed – 3–4 conjunctival biopsies each on upper palpebrum, upper bulbar, lower bulbar, and lower palpebrum [48, 49]. Extensive conjunctival involvement and/or orbital invasion portends a poor prognosis resulting in exenteration [19].

26.5.3 Oil Red O and Sudan Black Stains

If the diagnosis of SC is known to the Mohs surgeon and/or dermatopathologist in advance, Oil Red O may be used to highlight lipid. This stain is used only on frozen sections in which the solvent and alcoholic steps that dissolve lipid vacuoles are omitted. The frozen slides lack eosin counter stain. When SC comes into a pathology lab as an unknown, the tissue is placed in the automated tissue processor. There are more than 6 alcoholic steps that dissolve lipid making interpretation difficult (e.g., pagetoid SC looks like SCC in situ) [34, 50]. In a series of 20 cases, the initial clinical diagnosis was incorrect in all cases, and half the cases were misdiagnosed by the pathologists interpreting the initial biopsy [51]. Reengineering the protocols for lipid staining is not always practical because in many

cases the diagnosis is not suspected until after the tissue is embedded in paraffin [52]. Sudan IV stains lipid black [17, 42]. Also, both stains may not stain every atypical sebocyte because the sebocytes may be too poorly differentiated to contain any lipid [52]. Still, use of Oil Red O may be useful for pagetoid SC [14].

26.5.4Traditional Wide Local Excision (WLE)

Traditional excision with a wide tumor margin is the main method that oculoplastic surgeons employ to excise SC. The tumor margin is then checked by general or ocular pathologists using frozen and/or paraffin sections cut vertically. The local recurrence rate with a 1–3-mm margins is 36%. Reportedly, 5-mm margins had no local recurrences [53]. Shields et al. reported that, following standard wide excision, there was local recurrence rate of 18%, regional metastasis of 8%, and 6% deaths [45].

26.5.5 Mohs Micrographic Surgery

If the cancer is a primary tumor, of short duration, less than 5 mm in size, and clinically confined to a single lid, a 3-mm margin is an acceptable starting point for Mohs surgery. Tumors that originate near the canthi and potentially involve both lids probably require more extensive Mohs surgery with at least a 5-mm margin, providing there is oculoplastic availability. In Yount’s series [17], their initial Mohs layer was 5 mm around the primary tumor. This margin cleared the tumor in six of seven primary tumors. One case required three layers. Fast-track, 24-hour paraffin sections were used in nearly all cases. There were no recurrences with a follow-up range from 34 to 84 months. The case that required extra Mohs stages was a 15-mm primary SC that involved the lateral canthus and more than half of both lids. The single failure was a recurrent tumor of the inner canthus. The tumor was treated twice before Mohs surgery. At 3 years post Mohs, the tumor recurred locally with a neck node metastasis. The patient was treated by exenteration, maxillectomy, and neck dissection and was tumor free for another 3 years.

In a preliminary report by Ilyas et al. [54], at the University of Wisconsin, Mohs Surgery Clinic, there were 16 patients with SC of the eyelid treated from 1987 to 2008. The local success rate was 93% with a follow of 7 months to 14 years.

26.5.6 Surgical and Tissue Processing Issues

Mohs surgeons who regularly operate on the lids for BCC and SCC know that the evaluation of the conjunctival epithelial margin is critical for a successful outcome. The epithelium is thin, fragile, and easily destroyed by rubbing, curettage, and/or electrocautery. The epithelium shrinks after removal, and it is difficult to section 100% of the epithelial margin. To obtain good horizontal sections, the epithelium should be attached to a tissue lattice such as dermis or submucosa to provide structure and prevent the epithelium from folding over itself during the flattening procedure.

26.5.7 Frozen Sections

Mohs surgery is an efficient method to remove SC using frozen sections. Both the invasive and epithelial components of SC are recognizable by frozen sections. A disadvantage of frozen sections is that it may contain freeze artifact that hinders tumor cell recognition in the epithelial conjunctiva. Taking an extra epithelial layer is helpful to provide assurance, or referral to a tertiary center may be considered.

26.5.8 Paraffin Sections

Submission for paraffin sections should be planned beforehand with a dermatopathologist, so s/he knows what to look for in the sections. Paraffin sections have two advantages. First, when surgery is performed over two or more days, there is usually an inflammatory infiltrate that may hide atypical sebocytes. Second, SC is a difficult cancer, and the extra margin allows the Mohs surgeon/pathologist an opportunity double check their findings. The disadvantage is that most non-Mohs technicians who only work in paraffin labs have trouble in getting a complete horizontal layer, resulting in an incomplete margin check. Oil red O and Sudan black can not be performed on paraffin sections.

26.5.9 Exenteration

Exenteration is the removal of the eye (and lids) and other orbital contents within the bony walls of the orbit and neighboring sinuses [1]. The accepted indications