Home > ERN > Masocytosis



Versione in italiano

Masocytosis is characterized by abnormal proliferation and growth of mast cells in organs or tissues. It is defined cutaneous mastocytosis (CM) if mast cells are localized only in the skin, while if pathological mast cells grow in every other organ or tissue as bone marrow, gut, lungs, liver, spleen, or lymph nodes it is called systemic mastocytosis (SM).
In SM, it is frequent to find the somatic mutation of KIT gene, which codify for Stem Cell Factor receptor. Mastocytosis is a rare disease, having a light majority in men (men:women ratio is reported to be variable from 1:1 to 3:1). We estimate there are about 1000 people affected by CM or SM in Italy. This is not a genetic disease and it can appear in every moment of life, sometimes even at birth time.
CM is more common in children: about 50% of them show typical skin lesions in the first 6 months of their lives, but up to 90% recover spontaneously during adolescence. SM, instead, is common in adult, frequently affecting patients older than 20 years.
Clinical presentation is extremely heterogeneous: patients can show only skin lesions or they can have severe symptoms with organ impairment that can affect quality of life and need to be treated. Among these symptoms, the most dangerous and life-threatening are anaphylactic reactions that consists in rapid and unexpected blood pressure reduction, breath distress, abdominal pain and faint; these episodes need a urgent management into emergency room. Onset of flares, flushings, itch, rash or anaphylaxis can be caused by different triggers as food, drugs, insect bites, mechanical, physical, thermic or emotional stress.
Patients with CM frequently present with itch, but they can also have urticaria (weals), blisters or nodules. SM patients may never experience skin lesions but they can have, instead, flares, flushings, headhache, fatigue, blood pressure drop, nausea, diarrhoea, abdominal pain and osteoporosis. In rare cases, mastocytosis can be associated with other blood tumours.

Recognizing the typical skin lesions can help suspecting mastocytosis, but this could be more difficult in patients without skin manifestations; in these cases, diagnosis comes after multiple anaphylactic events and allergological evaluations.
Usually diagnosis is made after many years from the first clinical episode (median time for diagnosis: 3.5 years). Histological examination of the organ or tissue affected by mastocytosis is essential for diagnostic confirmation.
Bone marrow sample is not required in children, while it’s usually recommended in adults (when specific criteria are met). Blood laboratory tests can help, especially serum tryptase levels (a mastocyte specific protein).
After histological confirmation of mastocytosis, we recommend performing a Dual Energy X-ray Absorptiometry (DEXA) to evaluate the presence of osteoporosis, even in young patients.

Nowadays, we do not have a specific treatment to cure mastocytosis for good. As we previously said, children often recover spontaneously so they don’t need any treatment; in adult, therapy aims to treat and prevent symptomatic event, inhibiting the mastocyte protein release.
Patients with mastocytosis should always bring themselves adrenalin auto-injections to use in case of emergency, because they can have life-threatening events such as anaphylaxis. Exposition to ultraviolet rays (UVA) and pro-drugs like psoralen can be useful to reduce skin lesions.
Gastrointestinal discomfort can be treated with protonic pump inhibitors or antihistaminic anti-H1. Cromolyn sodium and ketotifene, antihistaminic, steroids and adrenaline help to block mastocyte degranulation and their negative effects. Bone pain and osteoporosis can be treated with calcium, vitamin D or bisphosphonates. Aggressive forms of mastocytosis need to receive chemotherapy (such as cladribine or hydroxyurea) or biologic agents like interferon, to reduce the tumor burden. New drugs are represented by tyrosine kinase inhibitors (imatinib, dasatinib, midostaurin), which block c-KIT cascade and can be useful in some settings. Patients don’t need to follow any food restrictions, unless there are evidences of food allergies.

We perform haematological evaluation – eventually joining also allergological, dermatological, gastroenterological and endocrinological evaluation – in order to make a correct diagnosis. We can assess the opportunity to start a specific treatment and manage the patient during therapy. If only follow-up is required, we perform periodic clinical evaluation with laboratory blood tests and radiological exams.

REFERRING DOCTORS for this desease
at Ospedale San Raffaele

Ospedale San Raffaele - Milano, via Olgettina 60, 20132 Milano, Italia - Tel. 02 26 431
"Le informazioni medico-scientifiche che si trovano in questo sito si intendono per un uso
esclusivamente informativo e non possono in alcun modo sostituire la visita medica."
Questo sito non utilizza alcun tipo di cookie.
Copyright Reserved © 2012 - 2015 Ospedale San Raffaele - Milano - P.I. 07636600962 - credits

Privacy Policy

Cookie Policy