What is Microcystic Adnexal Carcinoma?
Microcystic adnexal carcinoma (MAC) is a rare cancer of sweat glands that often develops on the head and neck. Although it mostly appears on the face, it can also appear on the trunk, armpits, limbs and genitals. What makes MAC unique is its slow development, but it can become quite aggressive locally.
It’s worth noting that there have been only about 200 cases reported worldwide. The cancer was first described by a researcher named Goldstein and his colleagues in 1982.
MAC is known by many other names, including:
* Sclerosing sweat duct carcinoma (SSDC)
* Malignant syringoma
* Syringoid eccrine carcinoma
* Eccrine epithelioma
* Syringomatous carcinoma
* Sweat gland carcinoma with syringomatous features
One type of tumor, called syringomatous adenoma of the nipple, is sometimes classified as MAC, but this is a topic of debate. MAC is often associated with perineural invasion, which means it spreads along nerve tissues. This occurs in about 80% of cases. It also advances beyond the areas that show obvious signs of the disease. However, it rarely spreads to other parts of the body, but it does often come back after treatment.
What Causes Microcystic Adnexal Carcinoma?
Certain factors have been shown to potentially lead to MAC, which is a type of skin cancer:
* Exposure to ultraviolet (UV) light
* Having had radiation therapy in the past
* The use of medications that suppress the immune system
The linkage between MAC and past radiation therapy is estimated to range from 19% to 50%. In these cases, MAC often appears 30 to 40 years after the radiation therapy was completed. UV light is frequently pointed out as a cause because MAC commonly appears in areas of the skin that have been exposed to the sun, especially in people with very fair skin (referred to as Fitzpatrick skin types I and II).
There have also been reports of MAC in young people who have had intense exposure to UV light, for example, fighter pilots.
Currently, it is not clear how immunosuppression – a condition in which the immune system’s ability to fight off illnesses is reduced – might increase the risk of developing MAC. However, it is known that immunosuppression does increase the chances of getting other types of skin cancer, such as basal cell carcinoma and squamous cell carcinoma.
Risk Factors and Frequency for Microcystic Adnexal Carcinoma
Microcystic Adnexal Carcinoma (MAC) typically develops in adults aged 55 to 60, but it has also been observed in children. It affects both males and females equally, although some research suggests that it might be slightly more common in females.
Signs and Symptoms of Microcystic Adnexal Carcinoma
Microcystic adnexal carcinoma is a medical condition that presents as a lone white to pink flat patch on the face or body. Early stages of this tumor may exhibit a slightly raised appearance. However, as time passes, it typically becomes more knob-like or nodular in appearance.
Testing for Microcystic Adnexal Carcinoma
MAC, which stands for Microcystic Adnexal Carcinoma, is a type of skin growth that can sometimes be hard to distinguish from other skin problems, especially on the head and neck. Some signs of MAC might include numbness, tingling, pain, burning, or itching.
In order to correctly diagnose MAC, an adequate skin sample (biopsy) needs to be taken. The tumor often exists deep within the skin, making a shallow biopsy ineffective for accurate identification. If your doctor suspects that you may have MAC, they will avoid a superficial biopsy which could lead to a wrong diagnosis, and might recommend a different type of biopsy such as an incisional biopsy, where a small cut is made into the skin to take a sample. Punch biopsies and excisional biopsies, where a small or a complete section of the suspicious area is removed for examination, are also possible methods used to diagnose MAC.
If the biopsy results confirm that you have MAC, it is recommended to have a complete skin examination. This is to check your entire body for any areas that might also be affected.
The doctor will also examine your lymph nodes to see if the MAC has spread, although this is not common. If your lymph nodes are enlarged, the doctor may use a needle to draw out cells for examination, or may suggest removing the lymph node completely to check for MAC cells.
Your doctor may also suggest an imaging test like a CT scan or MRI, especially if the MAC might have spread into the nerves–a condition called perineural invasion, or if it’s within your eye socket area.
Dermoscopy, a method that uses a magnifying tool to examine the skin, isn’t particularly effective for a clear diagnosis of MAC, mainly because it’s relatively rare. The few reports that exist suggest that the presence of white specks of various sizes could indicate MAC. These white specks are believed to be keratinous cysts, or tiny pockets filled with skin protein. MAC can look similar to another type of skin cancer called basal cell carcinoma due to the appearance of branching blood vessels in both types of tumors. However, this information is based on only a few case reports, so it may not apply to everyone.
Treatment Options for Microcystic Adnexal Carcinoma
There are two main ways of treating MAC (Microcystic adnexal carcinoma), a skin condition. One is by simple removal of the affected portion of the skin, and the other is the Mohs Micrographic Surgery (MMS). This type of surgery involves gradually removing thin layers of cancer-containing skin and examining under a microscope until only cancer-free tissue remains.
Interestingly, both these methods have a similar rate of complications. However, using Mohs surgery usually means fewer procedures are needed to make sure no cancer cells are left, leading to fewer trips to the doctor’s office.
Sometimes, though, Mohs surgery might not be a suitable option due to either lack of availability or because the tumor is too large. In these cases, intraoperative frozen sections can be used to guide the conventional surgical removal of the tumor. This technique involves freezing a thin layer of tissue, then examining it under a microscope to check for cancer cells.
After the treatment, it is important to keep a regular check on things. Therefore, patients are recommended to have full-body skin check-ups and lymph node examinations every six to twelve months.
What else can Microcystic Adnexal Carcinoma be?
MAC, a type of skin condition, usually appears on the face as a small bump or patch. There are many conditions that it can be mistaken for, but there are a few key ones that doctors need to consider when diagnosing:
- Morpheaform basal cell carcinoma, a type of skin cancer
- Desmoplastic squamous cell carcinoma, another type of skin cancer
- Desmoplastic trichoepithelioma, a benign skin tumor
- Trichoadenoma, a type of skin tumor
- Syringoma, a benign growth of sweat glands
Surgical Treatment of Microcystic Adnexal Carcinoma
Currently, medical guidelines do not suggest using a sentinel lymph node biopsy (a test that helps determine if cancer has spread within the body) to stage or determine the extent of Mucoepidermoid carcinoma (MAC), a type of cancer. There isn’t sufficient evidence to justify performing neck dissection, which is a surgical procedure, if a lymph node is found to be positive for cancer at the initial presentation.
When the disease has spread to the lymph nodes or other parts of the body (a condition commonly known as metastatic disease), the treatment recommended is surgery. This procedure should be performed in accordance with the procedures for local diseases; in other words, it should be treated as if it were a problem occurring in a particular part of the body.
What to expect with Microcystic Adnexal Carcinoma
The main worry with MAC, or a type of tumor, is that it might come back. This usually happens within two to three years, but it can even occur several decades later. MAC tends to be a locally aggressive tumor, which means it grows and spreads in the area where it started. On the other hand, it rarely spreads to other parts of the body, a process known as metastases.
MAC tumors can be serious if they begin to invade important structures within the body, which, in some cases, can result in death.
Possible Complications When Diagnosed with Microcystic Adnexal Carcinoma
If tumors are not treated, they can get more aggressive and start invading nearby areas. The complications arising from this will vary depending on where the tumor is located because they can affect important body structures. In severe cases, these complications can even lead to death.
Possible Complications:
- Aggressive invasion of tumors
- Invasion of vital body structures
- Potential death
Preventing Microcystic Adnexal Carcinoma
Patients should be informed that MAC, or Mucoepidermoid Carcinoma, is a type of tumor that grows slowly. It’s crucial for patients to understand the importance of regular check-ups because this condition can recur, even many years later in some cases.
