Sebaceous Carcinoma

Sebaceous carcinoma is a rare and aggressive type of cancer that begins in the sebaceous glands, which are tiny oil glands in your skin. These glands produce an oily substance called sebum. While it most often appears on the eyelids, it can develop anywhere on the body where sebaceous glands are present.

What is Sebaceous Carcinoma?

Sebaceous carcinoma is a rare and aggressive form of skin cancer that starts in your body's sebaceous glands. These glands are small oil-producing structures found in your skin, primarily responsible for keeping your skin and hair moisturized. This cancer can grow quickly and has the potential to spread to other parts of the body if not treated early.

Sebaceous glands are located throughout your skin, but they are especially concentrated on your face, scalp, and eyelids. Sebaceous carcinoma most commonly develops on the eyelid, making up a significant portion of eyelid cancers. However, it can also appear on other areas of the head and neck, or less frequently, on other parts of the body. This type of cancer is considered aggressive because it can grow quickly and may spread to nearby tissues or lymph nodes. In some cases, it can spread to distant organs, a process called metastasis. Because of its aggressive nature, early detection and treatment are very important for a better outcome. Sebaceous carcinoma is relatively uncommon compared to other skin cancers like basal cell carcinoma or squamous cell carcinoma. Its rarity can sometimes make it challenging to diagnose, as its appearance can mimic more common, non-cancerous skin conditions.

Symptoms

Sebaceous carcinoma often appears as a painless lump or growth on your skin, most commonly on the eyelid. This growth might be yellowish, firm, or have a crusty surface. It can sometimes bleed or form a sore that does not heal, and it may be mistaken for other common eyelid conditions like a stye or chalazion.

The most common symptom of sebaceous carcinoma is a painless, firm, yellowish lump or nodule. This growth often develops on the eyelid, either on the upper or lower lid. It might also appear as a crusty sore that does not go away, or a growth that bleeds easily. Because of its appearance, sebaceous carcinoma on the eyelid can often be confused with more common, non-cancerous conditions. For example, it might look like a stye (a painful, red lump near the edge of the eyelid) or a chalazion (a firm, painless lump in the eyelid caused by a blocked oil gland). However, unlike a typical stye or chalazion, a sebaceous carcinoma will usually persist or worsen over time. While the eyelids are the most frequent site, sebaceous carcinoma can also appear on other parts of the body where sebaceous glands are present. These include the face, scalp, neck, and even the trunk or genitals. Regardless of location, any new or changing skin growth that doesn't heal should be evaluated by a doctor.

Causes & risk factors

The exact cause of sebaceous carcinoma is not fully understood, but it involves genetic changes within the sebaceous gland cells. Certain factors can increase your risk of developing this cancer, including older age, previous radiation exposure, and having specific genetic conditions like Muir-Torre syndrome, which makes you more prone to various cancers.

Sebaceous carcinoma develops when sebaceous gland cells undergo mutations, or changes, in their DNA. These genetic changes cause the cells to grow and divide uncontrollably, forming a tumor. Why these specific mutations occur is not always clear, but they are typically acquired during a person's lifetime rather than being inherited. Several factors are known to increase a person's risk of developing sebaceous carcinoma. Age is a significant risk factor, with the cancer most commonly affecting older adults, particularly those over 60 years old. People who have received radiation therapy in the past, especially to the head and neck area, also have an increased risk. Another important risk factor is a rare inherited genetic condition called Muir-Torre syndrome. People with Muir-Torre syndrome have a higher chance of developing various internal cancers, as well as sebaceous adenomas (non-cancerous sebaceous gland tumors) and sebaceous carcinomas. If you have a family history of Muir-Torre syndrome or have been diagnosed with it, your doctor will likely recommend regular screenings for sebaceous carcinoma and other associated cancers.

How it's diagnosed

Diagnosing sebaceous carcinoma typically begins with a thorough physical examination of the suspicious growth, especially if it's on the eyelid. The definitive diagnosis requires a biopsy, where a small tissue sample is removed and examined under a microscope by a pathologist. Imaging tests may also be used to check if the cancer has spread.

When you see a doctor for a suspicious skin growth, they will first perform a physical examination. They will carefully inspect the lump or sore, noting its size, shape, color, and texture. If the growth is on your eyelid, they will also check your vision and the surrounding eye structures. The most crucial step in diagnosing sebaceous carcinoma is a biopsy. During a biopsy, a small piece of the suspicious tissue is carefully removed. This sample is then sent to a laboratory where a specialized doctor, called a pathologist, examines it under a microscope. The pathologist can identify the specific characteristics of sebaceous carcinoma cells, confirming the diagnosis. If sebaceous carcinoma is confirmed, your doctor may recommend further tests to determine if the cancer has spread. These tests can include imaging scans, such as a CT scan or MRI, to look for signs of cancer in nearby lymph nodes or other parts of your body. These steps help your medical team plan the most effective treatment.

Treatment options

The primary treatment for sebaceous carcinoma is surgery to remove the cancerous growth. Depending on the cancer's size and location, specialized surgical techniques like Mohs surgery may be used to preserve healthy tissue. Other treatments, such as radiation therapy, chemotherapy, or targeted therapy, may be considered for more advanced cases or when surgery is not possible.

Surgery is the most common and often the most effective treatment for sebaceous carcinoma. The goal of surgery is to remove the entire tumor along with a margin of healthy tissue around it to ensure all cancer cells are gone. For tumors on the eyelid, surgeons aim to remove the cancer while preserving as much of the eyelid's function and appearance as possible. One specialized surgical technique often used for sebaceous carcinoma, especially on the face or eyelids, is Mohs micrographic surgery. During Mohs surgery, the surgeon removes the cancer layer by layer, examining each layer under a microscope immediately. This process continues until no cancer cells are seen, which helps to remove all cancer while saving the maximum amount of healthy tissue. For more advanced cases, or if the cancer has spread, other treatments may be considered. Radiation therapy uses high-energy rays to kill cancer cells and can be used after surgery or as a primary treatment if surgery is not an option. Chemotherapy, which uses drugs to kill cancer cells throughout the body, is generally reserved for very advanced cases that have spread widely. Targeted therapy, which focuses on specific weaknesses in cancer cells, may also be an option in some situations.

Recovery & outlook

The recovery and outlook for sebaceous carcinoma depend heavily on how early it is detected and treated. With prompt and complete removal, especially for tumors that have not spread, the prognosis is generally good. However, this cancer has a notable risk of recurring, meaning it can come back, so regular follow-up appointments and monitoring are crucial after treatment.

After treatment for sebaceous carcinoma, your recovery will involve healing from surgery or other therapies. If you had surgery on your eyelid, you might experience some swelling, bruising, or temporary changes in your vision. Your doctor will provide specific instructions for wound care and any necessary follow-up care. The outlook for sebaceous carcinoma is generally better when the cancer is detected and treated early, before it has had a chance to spread. The size of the tumor, its location, and whether it has spread to lymph nodes or other parts of the body are all factors that influence the prognosis. Your medical team will discuss your specific situation and what to expect. Sebaceous carcinoma has a higher risk of recurrence compared to some other skin cancers. This means that even after successful treatment, the cancer can return, either in the same spot or nearby. Because of this, regular follow-up appointments with your dermatologist or oncologist are extremely important. These appointments typically involve thorough skin exams and sometimes imaging tests to monitor for any signs of recurrence or new growths.

When to see a doctor

You should see a doctor if you notice any new or changing skin growth, especially on your eyelid, that doesn't heal, bleeds, or changes in appearance. Pay close attention to any yellowish lump, a crusty sore, or a growth that you initially thought was a stye or chalazion but persists or grows larger over time.

It is important to seek medical attention promptly if you observe any suspicious changes on your skin. Specifically, if you have a new lump or growth that appears on your eyelid or anywhere else on your body, it warrants evaluation. This is particularly true if the growth is yellowish, firm, or has a crusty surface. Another red flag is a sore or growth that bleeds easily or does not heal within a few weeks. While many skin changes are harmless, persistent bleeding or non-healing sores can be signs of skin cancer, including sebaceous carcinoma. If you have a lump on your eyelid that you initially believed to be a common condition like a stye or chalazion, but it does not improve with home remedies, gets larger, or changes in appearance, it is crucial to have it checked by a doctor. Early detection of sebaceous carcinoma significantly improves treatment outcomes.

Frequently asked questions

Is sebaceous carcinoma always on the eyelid?

No, while sebaceous carcinoma most commonly appears on the eyelids, it can develop anywhere on the body where sebaceous glands are present. These glands are found throughout the skin, including the face, scalp, neck, and less frequently, other areas of the body.

Can sebaceous carcinoma spread to other parts of the body?

Yes, sebaceous carcinoma is considered an aggressive cancer and has the potential to spread. It can spread to nearby tissues, lymph nodes, and in some cases, to distant organs, a process called metastasis. Early detection and treatment are crucial to prevent spread.

What does sebaceous carcinoma look like?

Sebaceous carcinoma often appears as a painless, firm, yellowish lump or nodule. It can also look like a crusty sore that doesn't heal, or a growth that bleeds easily. On the eyelid, it might be mistaken for a stye or chalazion.

Is sebaceous carcinoma related to sun exposure?

Unlike many other skin cancers, sebaceous carcinoma is not primarily linked to sun exposure. Its exact cause is unknown, but it involves genetic changes in sebaceous gland cells. Risk factors include older age, prior radiation exposure, and certain genetic syndromes like Muir-Torre syndrome.

What is the main treatment for sebaceous carcinoma?

The main treatment for sebaceous carcinoma is surgery to remove the cancerous growth. Specialized techniques like Mohs micrographic surgery are often used, especially for tumors on the face or eyelids, to remove the cancer while preserving healthy tissue. Other treatments may be used for advanced cases.

How often does sebaceous carcinoma come back after treatment?

Sebaceous carcinoma has a notable risk of recurrence, meaning it can come back after treatment. Because of this, regular follow-up appointments with your doctor are very important to monitor for any signs of recurrence or new growths.

Sources

• MedlinePlus — Sebaceous Carcinoma
• Mayo Clinic — Sebaceous Carcinoma
• Cochrane Library — Sebaceous Carcinoma