What are the other Names for this Condition? (Also known as/Synonyms)

• ACC of Skin
• Adenocystic Carcinoma of Skin
• Cutaneous Adenoid Cystic Carcinoma

What is Adenoid Cystic Carcinoma of Skin? (Definition/Background Information)

• Adenoid Cystic Carcinoma (ACC) of Skin is a very rare and unusual form of cancer. It is typically observed in middle-aged and older adults and most of the cases are observed in the head and neck region
• A diagnosis of adenoid cystic carcinoma is established based on a tumor biopsy and examination under a microscope by a pathologist. Because of its rarity, it is often considered to be an ‘orphan tumor’. The rarity can pose diagnostic challenges and treatment difficulties
• The risk factors and cause of Adenoid Cystic Carcinoma of Skin are generally unknown. Genetic abnormalities have been observed in some tumors involving the MYB and NFIB genes
• Most tumors are solitary and painless and grow very slowly on the body, usually in the head and neck region; involvement of the surrounding nerves may be noted. In many cases, during the early stages (sometimes for many years), no significant signs and symptoms are noticed
• The treatment of choice is a surgical excision with clear margins followed by radiation therapy and/or chemotherapy, as decided by the healthcare provider. Close follow-up is necessary for several years after treatment, since 2 out of 3 carcinomas are known to recur after surgical removal
• In majority of the cases, the prognosis is good with appropriate early treatment. However, the prognosis of Adenoid Cystic Carcinoma of Skin also depends upon the stage of the tumor, health status of the individual, and whether it has metastasized

Who gets Adenoid Cystic Carcinoma of Skin? (Age and Sex Distribution)

• Adenoid Cystic Carcinoma of Skin is normally observed in adults in the age range 40-70 years (average age 58 years). Individuals of a wide age range may be affected
• Both males and females are affected, though the condition is slightly more common in females than males
• It is a very rare form of cancer. But, there is no predilection for any particular racial or ethnic group

What are the Risk Factors for Adenoid Cystic Carcinoma of Skin? (Predisposing Factors)

• The risk factors for Adenoid Cystic Carcinoma of Skin are currently not well-established
• Studies have not proven conclusively that smoking and excessive alcohol consumption are risk factors for ACC

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Adenoid Cystic Carcinoma of Skin? (Etiology)

The cause of development of Adenoid Cystic Carcinoma of Skin is unknown. Some tumors have displayed a fused gene product of chromosome 6 and chromosome 9, called MYB-NFIB gene. This fused gene is caused by the translocation of chromosome 6 and 9.

• In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor
• Many cancer types are caused by genetic mutations. These can occur, due to inherited mutations, or mutations that occur due to environmental factors
• The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
• These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body
• A poor diet and lack of physical activity may also contribute to the cause of cancer. Unhealthy food choices and avoiding physical activities can increase one’s likelihood of developing health risks, which could ultimately lead to cancerous tumor growth

What are the Signs and Symptoms of Adenoid Cystic Carcinoma of Skin?

Adenoid Cystic Carcinoma of Skin may present the following signs and symptoms:

• ACC is a slow-growing and painless tumor with a potential to invade into the surrounding tissues. In many individuals, often no significant signs and symptoms are seen for many months and years
• The tumor develops slowly and the growth rate varies from one individual to another. Often individuals have tumors growing for 5 years or more, after which they may present symptoms
• An unpredictable growth pattern is recognized; the tumor grows slowly during the initial stages, but a sudden rapid growth may be visible after a certain time duration
• The tumor infiltrates into the surrounding nerves and can cause pain, numbness, and tingling sensations
• It is typically seen as a solitary skin lesion that can vary in size from 1-10 cm, but is usually less than 5 cm
• The tumor is generally painless and grows slowly. However, it can ulcerate and bleed, and become painful
• It can occur on the head and neck region (especially scalp), chest, or abdomen skin
• If the tumor occurs on the scalp, it may be hairless around the tumor

How is Adenoid Cystic Carcinoma of Skin Diagnosed?

A diagnosis of Adenoid Cystic Carcinoma of Skin may involve the following:

• A thorough medical history and physical examination
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Note: A differential diagnosis, to eliminate other tumor types is considered, before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Adenoid Cystic Carcinoma of Skin?

The complications of Adenoid Cystic Carcinoma of Skin may include the following:

• Some individuals may have concerns regarding their cosmetic appearance
• The tumor can metastasize to the lymph nodes (local) and to the lungs
• Ulceration of the tumor can lead to secondary infections of bacteria and fungus
• In some occasions, tumor metastasis to distant sites including liver, lung, and bones, are observed. Metastasis often occurs due to a delay in diagnosis or due to a misdiagnosis
• Recurrence of the tumor after a period of time (usually few years), on incomplete removal; the percentage of recurrence is high at over 65%
• Side effects of chemotherapy (such as toxicity) and radiation
• Post-surgical infection at the wound site is a potential complication

How is Adenoid Cystic Carcinoma of Skin Treated?

The treatment of Adenoid Cystic Carcinoma of Skin usually involves surgery, which is the first treatment option considered. This is generally followed by radiation therapy. In case of metastasis, chemotherapy may be employed by the healthcare provider.

• In most cases, a wide surgical excision and removal of the entire tumor is the preferred treatment option. This may be followed by radiation therapy
• Mohs micrographic surgery is used to increase the likelihood of complete removal at one surgical session. Postoperative radiation therapy may be used as an adjunct
• If the tumor has metastasized, then a combination of chemotherapy, radiation therapy, and invasive procedures may be used to treat the tumor
• Post-operative care is important until the surgical wound heals
• Follow-up care with regular screening and check-ups are important and encouraged

How can Adenoid Cystic Carcinoma of Skin be Prevented?

• Currently, there are no known methods to prevent Adenoid Cystic Carcinoma of Skin occurrence
• Regular medical screening at periodic intervals with blood tests, scans, and physical examinations are mandatory, due to its metastasizing potential and high possibility of recurrence. Often several years of active vigilance is necessary

What is the Prognosis of Adenoid Cystic Carcinoma of Skin? (Outcomes/Resolutions)

• The prognosis of Adenoid Cystic Carcinoma of Skin is generally unpredictable and can only be assessed on a case-by-case basis. In some individuals, the life expectancy is long, even after metastatic stage (advanced disease)
• Studies show that some have lived for 30-40 years after diagnosis. However, in some, because of a rapid growth, the life expectancy may be substantially decreased to a few years. The tumors can recur years after surgery/radiation
• Also, despite a slow-growing growth pattern, the National Cancer Institute (USA) considers adenoid cystic carcinoma as a high-grade malignancy. Hence close follow-up for a long duration (sometimes, even for several decades) is necessary
• The prognosis of ACC of Skin depends upon a set of several factors, which include: 
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • The size of the tumor: Individuals with small-sized tumors fare better than those with large-sized tumors
  • Individuals with bulky disease may have a poorer prognosis
  • Involvement of vital organs may complicate the condition
  • The surgical resectability of the tumor (meaning, if the tumor can be removed completely)
  • Whether the tumor is occurring for the first time, or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur 
  • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment
  • Progression of the condition makes the outcome worse
• An early diagnosis and prompt treatment of the tumor generally yields better outcomes than a late diagnosis and delayed treatment. If metastasis (such as to the local lymph nodes or lungs) is observed, then the prognosis is unpredictable
• The combination chemotherapy drugs used, may have some severe side effects (such as cardio-toxicity). This chiefly impacts the elderly adults, or those who are already affected by other medical conditions. Tolerance to the chemotherapy sessions is a positive influencing factor
• Regular follow up visits with the healthcare provider are important, since recurrence of the tumor may occur many years after treatment of the condition

Additional and Relevant Useful Information for Adenoid Cystic Carcinoma of Skin:

• There is no evidence to prove that Cutaneous Adenoid Cystic Carcinoma formation is influenced by one’s dietary choices
• Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that could potentially worsen the condition
• The presence of dirt on the body is not a causative factor for the condition. However, it helps to be clean and hygienic, which may help the condition from getting worse

The following DoveMed website links are useful resources for additional information:

http://www.dovemed.com/diseases-conditions/cancer/