What is Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma?
Microcystic adnexal carcinoma (MAC) is a rare skin tumor that affects both follicles, the tiny sacs that hairs grow out of, and sweat glands. This was first identified by Goldstein and Barr in 1982. This condition is also known by several other names, including sclerosing sweat duct carcinoma, malignant syringoma, aggressive trichofolliculoma, combined adnexal tumor of the skin, and syringomatous carcinoma. There’s a debate on whether syringomatous adenoma of the nipple also falls under MAC.
MAC is considered a slow-growing but invasive and deeply impacting tumor, typically found on the head and neck area. It’s especially known for its tendency to invade the surrounding nerve tissue (in up to 80% of cases) and to infiltrate far beyond the visible boundaries of the tumor. MAC most commonly spreads through local invasion, with only a few cases showing spread to nearby lymph nodes. When this tumor invades muscle, fat tissue, and nerves, it can result in significant health issues.
Because of MAC’s aggressive nature and deep invasion, it’s crucial to completely remove the tumor, ensuring that no traces are left behind. However, MAC has a relatively high chance of coming back even after standard-wide local excision, with some reports showing a 60% recurrence rate. Mohs micrographic surgery, a precise surgical technique used to treat skin cancer, has shown more promising results with lower recurrence rates.
What Causes Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma?
Microcystic adnexal carcinoma is a type of skin tumor often found on the face of middle-aged and old adults. What may increase the risk of this tumor are:
* Exposure to ultraviolet (UV) sunlight.
* Prior radiation therapy, used to treat other diseases like cancer.
* Having a weaker immune system or taking medication that weakens the immune system.
* Having family members who have had this type of cancer.
An interesting point about this skin tumor is that it has been seen more often in people with Fitzpatrick skin types I and II, which are skin types more susceptible to sunburn. This has been observed in 19% to 50% of these individuals specifically, after they had undergone radiation therapy, with the tumor forming about 30 to 40 years later.
While we know that having a suppressed immune system can increase the risk of skin cancers like squamous cell and basal cell carcinoma, it’s not clear if it also increases the risk of developing microcystic adnexal carcinoma.
Risk Factors and Frequency for Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
Microcystic adnexal carcinoma is a rare type of cancer that commonly appears in people aged between 40 and 60. It affects both males and females fairly equally, although there are slightly more cases in females. The number of people diagnosed with this condition ranges from 1.6 to 6.5 out of 10 million individuals. From 1973 to 2004, a total of 223 cases were identified in the National Cancer Institute’s records.
While it’s often seen in white people, there have been reported cases in Japanese, Indian, and African-American populations as well. Around 10% of people with this cancer have a history of exposure to radiation, with an average of 30 years passing between the time of exposure and the development of the disease. It’s also believed that exposure to ultraviolet radiation and having a weakened immune system may increase the risk of developing this condition.
- Microcystic adnexal carcinoma is a rare cancer, typically appearing between ages 40 and 60.
- It affects both sexes, with a slight increase in females.
- Annually, 1.6 to 6.5 per 10 million get diagnosed with this cancer.
- There have been 223 cases listed in the National Cancer Institute’s records from 1973 to 2004.
- Most patients are Caucasian, but cases have also been reported in Japanese, Indian, and African-American communities.
- Previous exposure to radiation is a common factor in 10% of cases, with an average of 30 years from exposure to development.
- Increased risks exist for individuals exposed to ultraviolet radiation or who have a suppressed immune system.
Signs and Symptoms of Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
Microcystic adnexal carcinoma, often named ‘MAC’, is typically seen in middle-aged to elderly Caucasian individuals. This skin condition shows up as a slow-growing hard whitish or pinkish lump, patch, or growth often found on the head and neck. Although most cases are found on the head and neck, some instances have been reported on the trunk, armpits, and buttocks.
MAC is generally slow to develop and may initially look harmless, often being present for many years before being diagnosed. It typically appears as a vaguely outlined, skin-colored, or yellow lesion with tiny, visible blood vessels on the surface. The surface of the tumor is usually smooth and non-eroded, but the skin over the tumor may appear thinned or cracked.
When diagnosed, the average size of a MAC is around 2cm, but larger lesions have been reported. Interestingly, these lesions are often without symptoms; however, when symptoms do occur, they can include pain, burning, and unusual sensations. These symptoms might be due to the growth invading surrounding nerve tissues.
Testing for Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
In simpler terms, a flesh-colored skin tumor known as MAC is often hard to distinguish from other similar skin tumors on your head or neck. Unlike many other tumors, a MAC tumour can spread deeply into the skin and particularly prefers areas around nerve fibers, so it’s essential to diagnose it early to receive effective treatment promptly.
The best way to confirm a MAC diagnosis early is by giving a sample to a skin pathologist (a scientist who studies diseases) via a biopsy, which is a procedure where a small sample of tissue is taken from the body for examination. The pathologist needs to see the tumor’s depth within the skin and whether it has invaded nerve fibers – so a deep sample is preferred. A superficial (not so deep) biopsy may lead to a wrong diagnosis.
If a biopsy leads to a MAC diagnosis, a full-body skin examination should be performed to check if MAC has spread anywhere else.
Though it’s unusual for MAC to spread to nearby body parts, a lymph node examination should also be performed. Lymph nodes are small, bean-shaped glands throughout the body. They produce and store cells that help your body fight disease and infection. When inflammation in a specific area of the body occurs, the lymph nodes in that area may swell. If any swollen lymph nodes are detected during the examination, a procedure called a sentinel lymph node biopsy could be performed to check for cancer.
Imaging tests like CT, MRI, or a specific type of MRI that suppresses the appearance of fat might be considered if there’s concern about the cancer reaching the nerves or spreading locally. It’s important to remember that imaging tests are usually not necessary in most cases of MAC. An MRI can sometimes define the size of the tumor and find out if it has spread.
A specific skin imaging technique called Dermoscopy may also be used. It can highlight some unique signs of MAC, like the presence of white “clods” (little lumps of varying sizes), which probably represent keratinous cysts. Keratinous cysts are small, hard lumps that form in the skin when the skin cells multiply instead of being shed. In MAC, just like in a skin cancer called basal cell carcinoma, tiny branching blood vessels can also be present.
Treatment Options for Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
Microcystic adnexal carcinoma (MAC) is a type of skin cancer that is typically treated using surgery. There are two possible surgical methods: wide excision and Mohs micrographic surgery. Wide excision is a method that involves removing a large area surrounding the tumor. The aim of this surgery is to ensure that as much of the cancerous tissue is removed as possible. However, this method often has high recurrence rates of 40% to 60%, which means the cancer comes back in the same place.
Mohs micrographic surgery (MMS), on the other hand, is the preferred treatment since it offers higher chances of completely curing the tumor while preserving the healthy tissue around it. The surgeon removes the visible tumor and a thin layer of tissue around it. Then, while the patient waits, the tissue is examined under a microscope to check if it contains cancer cells. This process is repeated until no more cancerous cells are identified. Despite this careful approach, surgeries often result in tissue defects that are often larger than expected, indicating that it’s difficult to accurately identify the full extent of the tumor visually before the operation.
Because MAC often grows invisibly beyond the visible tumor margins and can infiltrate nerves (a condition known as perineural invasion, or PNI), a method that allows detailed examination of the entire surgical margin like MMS is recommended. However, as with all surgeries, removal of the tumor might leave a significant defect in the skin which might need to be reconstructed using skin grafts or flaps of skin moved from adjacent areas.
Lymph node testing is typically not required as MAC very rarely spreads to lymph nodes. Radiation therapy is generally not recommended as a standalone treatment because MAC is resistant to it. However, it may be used as an additional treatment, particularly if cancer cells have invaded the nerves or the tumor couldn’t be entirely removed through surgery. In rare instances, patients who didn’t undergo surgical treatment received a combination of chemoradiation, a treatment that combines chemotherapy and radiation therapy, with successful results.
Finally, frequent follow-up appointments will be necessary after treatment. The frequency will depend on the extent of the tumor and the individual patient’s risk. After surgery, patients also need to take precautionary measures such as protecting their skin from sunlight, regular self-checks for any changes in their skin, post-operative care, and managing their expectations about changes in sensation and scars resulting from the surgery.
What else can Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma be?
When diagnosing MAC (Microscopic Adenocarcinoma), doctors take into consideration other conditions that share similar symptoms. These include:
- Morpheaform Basal Cell Carcinoma
- Desmoplastic Trichoepithelioma
- Metastatic Adenocarcinoma
- Syringoma
Each of these conditions has specific features that helps physicians differentiate them from MAC:
- Morpheaform Basal Cell Carcinoma: Characterized by thin strands of cells under the skin, a limited cellular pattern known as ‘palisading’, a dense, hard layer of tissue (stroma), and can often involve nerves.
- Syringoma: This condition presents with a superficial expansion of cells that form uniform-sized nests and tube-like structures. These structures can look like commas or tadpoles. The tube-like areas have duct-like features. Also, cysts and hard bumps (milia) can be noted. This condition is often difficult to distinguish from others, like sclerosing BCC, desmoplastic trichoepithelioma, MAC, and metastatic carcinomas.
- Metastatic Adenocarcinoma: This type of cancer is identified by large abnormal cells that may or may not mimic ducts. These abnormalities are visibly noticeable under a microscope. This condition can also exhibit mitotic figures, which are signs of cell division.
- Desmoplastic Trichoepithelioma: Features of this condition include a dome-shaped lump with an invasive growth of abnormal cells, small tumor nests, cords, and a fibrotic stroma. This condition does not affect the sweat ducts and rarely invades the deep tissue beneath the skin.
These distinctive characteristics help medical professionals to accurately diagnose and treat the condition.
Surgical Treatment of Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
In simple terms, these points are explaining methods to investigate and treat Mucoepidermoid Carcinoma (MAC), which is a type of cancer. Medical studies suggest the following strategies:
Firstly, doctors don’t usually advocate for a technique called sentinel lymph node biopsy (SLNB) in staging MAC. In other words, they don’t generally use this procedure, which checks whether cancer has spread to the lymph nodes, for determining the severity or stage of this type of cancer.
Secondly, there’s currently no proof to support neck dissection – a surgery that removes lymph nodes in the neck – as a way to find positive or infected lymph nodes.
Last but not least, the characteristics of the disease at its original or ‘local’ site should guide the treatment strategy, even in cases where this type of cancer has spread to the lymph nodes or other parts of the body.
What to expect with Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
Microcystic adnexal carcinoma is a type of cancer that grows aggressively in the skin and can spread deep into tissue, often along nerve paths. It’s rare for it to spread to other parts of the body, but it has been known to happen. This cancer has a high chance of growing back, especially if the entire cancer wasn’t completely removed during surgery.
When looking at these cancers under a microscope, doctors often find that the cancer has spread farther than they can see with their eyes. Mohs Micrographic Surgery (MMS) is known to be the most successful treatment for these types of tumors. There have been cases where this type of cancer resisted radiation treatment, and in some cases, radiation may make the cancer more aggressive. Therefore, doctors suggest long-term check-ups for patients with this type of skin cancer, as there have been cases where cancer returned many years after initial treatment.
If left untreated, these tumors can rapidly spread and invade nearby areas. Although it’s rare, these can eventually spread to distant parts of the body and may cause death. Based on previous studies, doctors have several recommendations:
1. If a skin lesion is suspected to be microcystic adnexal carcinoma, a deep biopsy is needed. This is a type of test where a small piece of the skin, which includes the deeper layers, is removed for examination.
2. The best treatment for this type of skin cancer is surgery which completely removes the tumor. Doctors will also check the surrounding deep tissues to ensure no cancer is left behind.
3. Although radiation therapy is a common treatment for different types of cancers, its effectiveness in treating microcystic adnexal carcinoma is still under debate. It is mostly used as a supportive treatment, for patients who are not suitable for surgery, or when cancer was not fully removed during surgery.
4. Patients should have regular check-ups every 6 to 12 months for the first five years following treatment.
5. Doctors also advise patients to limit their exposure to sunlight and to have regular skin examinations to timely detect any changes or signs of recurrence.
Possible Complications When Diagnosed with Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
The primary complication of untreated MAC tumors is typically invasive growth at the local site, which can sometimes spread extensively along the nerves. However, rarely these tumors can spread to various parts of the body (this is known as metastasis) and occasionally result in death. A further concern is when these tumors affect vital body structures.
Complications of untreated MAC tumors:
- Invasive growth at the local site
- Extensive spread along nerves
- Distant metastasis or spread to parts of the body
- Potential death
- Affect vital body structures
Preventing Mohs Micrographic Surgery Evaluation and Treatment of Microcystic Adnexal Carcinoma
It’s important to let patients know that MAC, which stands for Microcystic Adnexal Carcinoma, is a type of slow-growing, persistent skin cancer that might be hard to detect in its early stages. Educating patients who have been treated for MAC about the critical role of follow-up examinations is crucial. This is because in some cases, this cancer can come back, even many years later. Practical steps like proper skin care to protect against sunlight (photoprotection), regularly checking your own skin, understanding what to expect in terms of wound healing after surgery, and knowing about potential changes in skin sensation can all be useful. They can all help to catch any new tumors or any return of the cancer as early as possible.
