Sebaceous gland carcinomas are exceedingly rare. They almost always present at the eyelid, as a persistent red-yellow bump The most common complaint of a patient will be a persistent sty that's not going away.
Only a biopsy can determine whether we have sebaceous cell carcinoma or not. It's important to make this diagnosis, not only for excision of the cancer, but also to make sure that you get examined for other types of cancer.
Specifically, in Muir-Torre syndrome people with sebaceous cell carcinoma can get carcinoma of their stomach or their colon. So people who have a diagnosis of sebaceous gland carcinoma should be referred to a gastroenterologist for endoscopy, as well as a colonoscopy.