5%, and melanoma and other malignancies account for 1% [19, 20]. For all SC sites, the SEER database shows that the median age was 73 years. The sex distribution for SC was about equal with men numbering 729 (52%) and women 620 (46%). The most frequent site for SC was the eyelid (38.7%). In the USA, the degree of previous radiation and ultraviolet exposure may play a larger role than racial factors. The SEER reports suggest that the incidence of SC is increasing possibly due to increased awareness, referrals to tertiary centers, and increased radiation exposure [7]. The SEER database did not break out the periorbital survival data.

Summary: Demographics

•Sebaceous carcinoma typically occurs on the upper eyelids in older Caucasian females with mean age of 72.

•Muir–Torre syndrome is associated more with sebaceous adenoma than sebaceous carcinoma.

•Risk factors for sebaceous carcinoma include older age, female sex, ethnicity (Caucasian, Asian, and Indians), irradiation, ultraviolet exposure, preexisting nevus sebaceous, Muir–Torre syndrome, and immunosuppression.

the stomach and duodenum and urinary tract. MTS is associated with microsatellite instability and mismatch repair genes. Occasional patients with the Muir–Torre syndrome have developed periocular sebaceous carcinoma. MTS is associated more with sebaceous adenomas than sebaceous carcinomas [24]. Cohen et al. [25] showed that 24.2% of 120 MTS patients had an SC.

26.2.3 Human Papillomavirus (HPV)

A study from Japan showed that 13 of 21 tumors (62%) were positive for HPV DNA using in situ hybridization techniques [26].

26.2.4 Other Risk Factors

Risk factors for sebaceous carcinoma include older age, female sex, ethnicity (Caucasian, Asian, and Indians), irradiation, preexisting nevus sebaceous [27, 28], Muir–Torre syndrome [29], and immunosuppression. There is no convincing data to support thiazide diuretics [30].

26.2Demographics

26.2.1 Age, Sex, Irradiation, Race

Sebaceous carcinoma is generally a disease of older individuals. The mean age is 72 (range 50–92) [19]. White women are predominantly affected, and the upper lid is affected twice as frequently as the lower lid. However, it can occur in children and young adults within 11 years after radiation for retinoblastoma [21]. Bilateral SC has been reported in a patient who had prior whole face irradiation for eczema [22]. Internationally, SC is reported as more prevalent in the Asia and India [2, 23]. In the USA, the SEER race distribution was Caucasian > Asian/ Pacific Islander > African American [7].

26.2.2 Muir–Torre Syndrome (MTS)

The Muir–Torre syndrome is an autosomal dominant condition in which patients develop cutaneous adenomas, keratoacanthomas, and internal malignancies mainly of

Summary: Clinical Presentation

•Sebaceous carcinoma can mimic both a neoplastic process and an inflammatory condition.

•It typically presents with multiphasic growth pattern: papular nodular tumor; in situ invasion of the epithelia; and multicentric lesions.

•It can resemble a sty, chalazion, pyogenic granuloma of the lid margin, or unilateral conjunctivitis.

26.3Clinical Presentation

Sebaceous carcinoma is known widely as the great masquerader because it can mimic both a neoplastic process and an inflammatory condition. Sebaceous carcinoma typically presents as a malignancy with multiphasic growth pattern: (1) papular nodular tumor, (2) in situ invasion of the epithelia, and (3) multicentric lesions. The most common presentation is a localized papular-nodular subcutaneous growth, resembling a sty, chalazion, or pyogenic granuloma of the lid margin. The color is usually yellow due to lipids (Figs. 26.1–26.4). About 40–80%

Fig. 26.1 Sebaceous carcinoma. An 82-year-old man with a lesion on the left inner canthus. The original biopsy was a chalazion. When it recurred, it was re-biopsied to be a sebaceous carcinoma. The patient was then referred to Mohs surgery for treatment (With permission, Snow et al. [31]. John Wiley & Sons)

Fig. 26.2 Sebaceous carcinoma. The tumor was excised in four stages of excision. The defect extended from the inner canthus and bridge to the lateral orbital commissure. The medial excision removed the upper and lower lid puncta and canaliculi. The overall size was 22 by 50 mm. About two-thirds of the upper lid was removed (With permission, Snow et al. [31]. John Wiley & Sons)

of SCs will also demonstrate invasion of the adjacent conjunctiva and/or epidermis [17, 31]. Perhaps 5% of SC will present as unilateral conjunctivitis showing only superficial changes in the epithelium. These lesions grow insidiously within the surface epithelium and have been confused with chronic conjunctivitis and/or squamous cell carcinoma in situ. A pattern of yellow “tigroid” streaks of lipid may be observed on the conjunctiva [32]. Involvement of the fornices or caruncle is the sign that is

Fig. 26.3 Sebaceous carcinoma. Advancement of the upper lid margin medially to partially close the defect and provide corneal protection (With permission, Snow et al. [31]. John Wiley & Sons)

Fig. 26.4 Sebaceous carcinoma. The defect was repaired by oculoplastic service. This is the follow photo at 1 year postoperatively. The patient is tumor free for 10 years (With permission, Snow et al. [31]. John Wiley & Sons)

more consistent with sebaceous carcinoma [29, 33]. Lastly, a small percentage of SC are multicentric being derived from meibomian gland, glands of Zeis (Fig. 26.5), or other orbital sebaceous gland.

Summary: Histopathology

•There are four classic invasive architectural patterns: (1) lobular, (2) comedocarcinoma, (3) papillary, and (4) mixed.