Excerpt from Sebaceous Gland Carcinoma

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Sebaceous glands are part of epidermal appendages. Neoplasms of the sebaceous glands may be benign, such as sebaceous hyperplasia or sebaceous gland adenomas. The malignant sebaceous gland carcinoma most commonly arises in the periocular area. Fewer than 120 cases of sebaceous cell carcinoma have been reported at extraocular sites. The most common site of origin is the meibomian glands of the eyelids, leading to the term meibomian gland carcinoma. However, this neoplasm can occur in other sebaceous glands, such as in the caruncle, the glands of Zeis, and in the eyebrow. Sebaceous cell carcinoma is a lethal eyelid malignancy and can masquerade as benign conditions. Error or delay in diagnosis is common, and this tumor carries a significant mortality rate with metastasis.

History of the Procedure

This type of tumor has been confused with other tumors both clinically and histologically.

Frequency

Incidence of sebaceous cell carcinoma is 3.2% among malignant tumors and 0.8% of all lid tumors. The mortality rate is 22%.

Sebaceous cell carcinomas are typically found in women, more often in the seventh decade of life, and they usually are on the upper lid margin.

Although sebaceous cell carcinomas are more common in elderly patients, they may be seen in younger patients with a history of radiation to the face.

Etiology

Carcinoma of the meibomian and Zeis glands

Pathophysiology

Sebaceous cell carcinoma may mimic either a chalazion or chronic blepharitis. It tends to invade locally, as well as spreading to regional lymph nodes. Sebaceous cell carcinomas may grow in nests with central necrosis. The intraepithelial spread may lead to the erroneous histologic diagnosis of epithelial dysplasia or carcinoma in situ.

Foamy cytoplasm is seen only in sebaceous carcinoma, but it is absent in conjunctival or cutaneous squamous cell carcinoma. It also can histologically mimic basal cell carcinoma, squamous carcinoma, or Merkel cell tumor.

Either fresh tissue or formalin-fixed tissue not exposed to alcohol can be frozen, and positive fat stains such as oil red O can confirm the diagnosis of sebaceous carcinoma.

Clinical

The clinical appearance of sebaceous gland carcinoma is highly variable. They simulate such benign conditions as chalazion, blepharoconjunctivitis, keratitis, and other malignant or benign skin lesions.

Many of the skin tumors have a predilection for the upper lid and have a yellowish appearance. Tumors at the lid margin commonly cause loss of eyelashes. Classically, this lesion is a firm, painless, indurated mass or ulceration associated with the loss of cilia, in an area that has been treated for recurrent chalazia.

Both the history and the presentation of sebaceous cell carcinoma are variable. Typically, there is an insidious onset of a painless firm eyelid mass. This mass easily can appear clinically as a recurrent or chronic chalazion. Sebaceous cell carcinoma also can mimic unilateral blepharoconjunctivitis, meibomitis, basal or squamous cell carcinoma, conjunctival or corneal carcinoma in situ, orbital inflammation, or superior limbic keratoconjunctivitis.

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