What is Mastocytoma?
A Mastocytoma is a type of tumor that affects mast cells. These cells originate from myeloid stem cells, which are a type of cell that can develop into many different types of blood cells. Mast cells are mostly found in connective tissues, particularly in the skin and the linings of the body’s passages, like the gut and the respiratory tract. These cells contain granules filled with substances like histamines and other immune system chemicals that are released in response to allergic reactions and some other immune responses.
When these mast cells start to multiply abnormally, it can cause various issues both within a specific area and more broadly throughout the body. This is referred to as ‘mastocytosis’. The World Health Organization recognizes it as a type of blood disorder. Mastocytosis often affects the skin, but can also impact other organs in what is known as systemic mastocytosis. In adults, the condition is usually chronic and affects multiple parts of the body. In contrast, in children, the symptoms are typically limited to the skin.
Skin-related mastocytosis can range from a single mastocytoma (tumor) to a widespread rash, most commonly known as urticaria pigmentosa (UP). This is a condition where red or brown patches or spots appear on the skin.
What Causes Mastocytoma?
The exact causes of this disease are not fully understood, but researchers have found some clues in the area of the body where the disease occurs. They’ve noted that there is a higher concentration of substances in the body called growth factors and interleukins, which can lead to the growth of certain cells called mast cells and melanocytes, and prevent these mast cells from dying off.
There could also be genetic components to this disease. Changes in a gene known as c-kit, might give a sort of “growth signal” to mast cells. However, this genetic change may not be the primary reason why these abnormal mast cells start to grow. There’s one change in particular, named the D816V mutation, that is seen frequently in those with the disease, both adults and children.
But it’s important to note, these gene mutations occur after birth and aren’t usually inherited from parents. Though there have been a handful of cases in families where it seems the disease might have been passed down from a parent to their child.
Risk Factors and Frequency for Mastocytoma
Cutaneous mastocytosis is a skin condition that mainly affects children, with most patients showing symptoms within the first two years of their life. This condition can sometimes be present from the time of birth. While it doesn’t favor any particular gender or race, cases appearing in adulthood are rare.
- Most cases of cutaneous mastocytosis manifest as patches or spots called Urticaria Pigmentosa, making up 70-90% of cases.
- Mastocytomas or nodular growths are also common, but less so, occurring in 10-35% of cases.
- The most uncommon form of this disease is diffuse cutaneous mastocytosis, affecting only 1-3% of patients.
- Mastocytomas usually appear as a single growth. However, if there are fewer than four lesions, it is still classified as mastocytoma.
Signs and Symptoms of Mastocytoma
Cutaneous mastocytosis is a skin condition that can affect any part of the body, though it is usually found on the chest area and the limbs. It shows up as spots or bumps that may be single or a few, varying in size, and look like yellowish brown patches, bumps or lumps. These spots are usually not painful but can sometimes cause intermittent redness and itchiness. If you scratch or rub these lesions, it might cause the mast cells in your body to release chemicals that lead to flushing, itching, and swelling of the skin. This is known as Darrier’s sign, a classic indication of this disease.
Blisters and large boils are more common in children under three years old and may be seen in severe forms of the disease that affect large areas of the body. The type of mastocytosis a person has is determined by the number of these lesions: if there are three or fewer nodules, it’s a type called mastocytoma. If it affects the whole body, the skin may become thick and leathery.
There’s another extremely rare form of this condition called Telangiectasia macularis eruptiva perstans, which presents as reddish patches with tiny visible blood vessels and may co-occur with the usual form. These skin issues do not leave a scar. In cutaneous mastocytosis, there is usually no systemic effects, meaning it doesn’t affect your overall body. However, symptoms like wheezing and fainting have been reported. 40% of children with this condition have also reported experiencing symptoms such as diarrhea. In rare cases, a severe reaction related to mast cells causing allergy-like symptoms could occur.
Testing for Mastocytoma
If your doctor suspects you might have a skin condition called cutaneous mastocytoma/mastocytosis, he or she will first look at the physical appearance of the spots on your skin. A symptom called Darrier’s sign can hint at this condition. However, to confirm it and to make sure it’s not simply an increase in mast cells or a reactive condition, more advanced tests are needed.
The World Health Organization, or WHO, has set guidelines to diagnose this disease. It involves a clinical evaluation, study of tissue under the microscope, and making sure the disease hasn’t spread to other parts of the body. A simple needle biopsy, where a small sample of the questionable tissue is removed with a fine needle, can be enough to identify abnormal growth of mast cells. But in some cases, a surgical biopsy might be needed to make sure of the diagnosis. Mast cells can sometimes look different under the microscope, varying from well-formed to poorly formed cells.
The disease is classified into four stages according to WHO standards. A skin test called dermatoscopy can be performed but the results can be vague and may not provide a specific diagnosis. Your doctor may also order some blood tests like a full blood count and a measurement of serum tryptase, a substance produced by mast cells, before starting your treatment.
Usually, the level of serum tryptase and involvement of bone marrow is not seen in children with this skin disease but can occur in adults. If the disease shows systemic symptoms in children, like fever and weight loss, abnormal blood tests results, unresponsive to usual treatments, and high levels of tryptase, your doctor might suggest a bone marrow evaluation for any abnormalities. An ultrasound scan of the abdomen can also be done to make sure there are no enlarged organs.
Treatment Options for Mastocytoma
The treatment process helps manage symptoms and reduces factors that might lead to the release of mast cells. Mast cells are a part of the immune system that contributes to various allergic reactions. Some of these factors include harsh rubbing, changes in temperature, dryness, and so forth.
Generally, doctors recommend the use of oral antihistamines and creams with corticosteroids to help alleviate symptoms. Antihistamines help decrease your body’s reaction to allergens, and corticosteroids help reduce inflammation in the body.
Another form of treatment used is phototherapy, which uses light to relieve itchiness. However, more intense treatments like cytoreductive therapy and surgery are saved for severe systemic cases. Systemic cases refer to conditions that impact the entire body rather than just one specific part.
The drug epinephrine, also known as adrenaline, should be used for any cases showing symptoms of a severe allergic reaction, also known as anaphylaxis. This injection helps to reduce your body’s allergic reaction and quickly improves breathing, stimulates the heart, raises dropping blood pressure, reverses hives, and reduces swelling of the face, lips, and throat.
What else can Mastocytoma be?
These are some conditions that can occur from birth or early in life:
- Congenital or early-onset melanocytic nevus (a type of skin mole)
- Juvenile xanthogranuloma (a skin condition often seen in young children)
- Tuberous xanthoma (a rare condition characterized by yellowish growths on the skin)
What to expect with Mastocytoma
Cutaneous mastocytosis, a skin condition, generally follows a mild course and tends to have a good long-term outlook. Children who get this disease before they turn 2 years old typically see the disease completely clear up by the time they’re 10 years old. However, in instances where the disease doesn’t clear up or appears after a child is 2 years old, it’s likely to persist.
In adults, this disease usually comes with symptoms that affect the whole body. Sometimes, cases that began in childhood and linger can also advance to affect the entire body. Children who get the disease after they’re 2 years old, experience symptoms beyond their teenage years, or have irregular blood counts face a higher risk of the disease affecting their entire body.
Both persistent cases and those that start in adulthood have a slight chance of taking a severe turn. This could involve the disease evolving into a malignant condition characterized by abnormal mast cells (a type of white blood cell) in the skin or blood. This severe transformation, however, is rare.
Possible Complications When Diagnosed with Mastocytoma
- Continuous sickness
- Whole body reactions including severe allergic reactions
- Rare cases of turning into a type of cancer called mast cell sarcoma or mast cell leukemia
Preventing Mastocytoma
Patients should try to steer clear of anything that might trigger their symptoms. Additionally, if a patient has a system-wide disease, they should understand there’s a risk of experiencing a severe allergic reaction, known as anaphylaxis. It’s strongly recommended that patients in this situation carry injectable epinephrine, a medication which can rapidly counteract these serious allergic reactions.
