Sebaceous carcinoma

Sebaceous carcinoma is a rare and aggressive form of skin cancer that originates in the sebaceous glands. These glands are responsible for producing sebum, an oily substance that helps to lubricate the skin and hair. Sebaceous carcinoma most commonly affects the eyelids, where it is known as ocular sebaceous carcinoma, but it can also occur in other parts of the body where sebaceous glands are present, including the face, neck, scalp, and genitalia.

Etiology and Risk Factors

The exact cause of sebaceous carcinoma is not well understood, but several risk factors have been identified. These include advanced age, a history of prolonged exposure to ultraviolet (UV) radiation, and immunosuppression. Individuals with Muir-Torre syndrome, a rare genetic condition characterized by the presence of sebaceous gland tumors and internal malignancies, are at a significantly increased risk of developing sebaceous carcinoma.

Symptoms and Diagnosis

Sebaceous carcinoma can present with a variety of symptoms, depending on its location. Ocular sebaceous carcinoma may manifest as a painless, firm, and slowly enlarging nodule on the eyelid, often mistaken for a chalazion or blepharitis. Non-ocular sebaceous carcinoma typically appears as a yellowish, firm, and painless nodule on the skin. Due to its nonspecific presentation, sebaceous carcinoma is often misdiagnosed, leading to delays in treatment.

Diagnosis of sebaceous carcinoma involves a thorough clinical examination followed by a biopsy of the lesion. Histopathological examination of the biopsy specimen is crucial for confirming the diagnosis. Immunohistochemistry may also be employed to differentiate sebaceous carcinoma from other types of skin cancer.

Treatment

The mainstay of treatment for sebaceous carcinoma is surgical excision with wide margins to ensure complete removal of the tumor. Mohs micrographic surgery, a technique that allows for the immediate microscopic examination of the excised tissue, is particularly effective in achieving clear margins while preserving as much healthy tissue as possible. In cases where the carcinoma has metastasized or is inoperable, radiation therapy and chemotherapy may be considered as adjunctive treatments.

Prognosis

The prognosis for sebaceous carcinoma varies depending on the stage of the disease at diagnosis and the completeness of tumor removal. Early detection and complete excision are associated with a favorable prognosis, while advanced disease, particularly with regional or distant metastases, has a poorer outcome.

Prevention

Preventive measures for sebaceous carcinoma include minimizing exposure to UV radiation by wearing protective clothing and using broad-spectrum sunscreen, as well as regular skin examinations for early detection of suspicious lesions. Individuals with a history of skin cancer or genetic predispositions should be particularly vigilant.