Mastocitose Sistémica

Likely to accompany othter associated hematological diseases
  • Myelodysplastic syndrome
  • Other myeloproliferative disorder
  • Mast cell leukemia
 
Diagnosis: bone marrow biopsy and/or mast cell phenotyping on myelogram (abnormal CD2 and CD25 expression) during assessments for anaphylaxis, flushing, hepatomegaly, skeletal abnormalities and/or blood count
 
Organs affected: organs normally rich in mast cells:
  • Bones - bone pain, pathologic fractures
  • Digestive tract
  • Hematopoietic organs: anemia, hypereosinophilia, splenomegaly, lymphadenopathy
  • Heart
  • Lungs
  • Pancreas
  • Kidneys
 
Diagnostic criteria
notion image
 
Geral de todas as mastocitoses (ver mastocitoses)
Histologia
  • Mastócitos têm grânulos metacromáticos que coram com toluidine azul
  • KIT membranar (CD117) é o marcador imunohistoquímico muitas vezes usado
 
DDx
  • Disorders that cause a secondary increase in mast cells
    • Parasitic infections
      • Toxoplasmosis
    • Allergic reactions (urticaria, insect bites)
    • Immunological reactions (GVHD, granulomatous reactions)
    • Benign tumors (hemangioma, neurofibroma)
    • Benign hematological disorders (thrombocytopenia, hypereosinophilic syndrome, porphyrias, Castleman’s disease)
    • Malignant disorders (Hodgkin’s and other lymphomas)
 
Exames complementares
  • Serum triptase
  • Urinary histamine
 
Tratamento
  • Prognosis for mastocytosis in children is almost always favorable. Pigmented urticaria regresses in half of cases around puberty, while congestive manifestations fade around the age of 2 or 3.
  • There is currently no cure
  • Elimintation of mast cell degranulation factors
    • Avoid: general anesthesia, imaging with iodinated contrast agents, medications
    • Introduction of drugs that may induce degranulation of mastcells must be carried out under strict medical supervision with paramedication with antihistamines
    • General anesthesia without precautions or without information from the anesthesiologist is considered high risk in these patients
  • Symptomatic treatment
    • Antihistamines
    • Proton pump inhibitor if peptic ulcer due to gastric histamine release
    • Disodium cromoglycate - mast cell membrane-stabilizer. 800mg/day for adults, 60-100mg/day for children
    • Phototherapy
      • PUVA, UVA1
    • Topical very strong corticosteroids
    • Adrenaline if signs of anaphylatic shock
    • Biphosphonates for bone pain and osteoporosis
  • If aggressive and/or symptomatic
    • Tyrosine kinase inhibitors
      • Imatinib, masitinib, midostaurin
      • Interferon
      • Chemptherapies
      • Allogenic bone marrow transplant