Systemic Mastocytosis Clinical Presentation

Updated: Jun 21, 2021
  • Author: Devapiran Jaishankar, MBBS; Chief Editor: Emmanuel C Besa, MD  more...
  • Print


Patients with systemic mastocytosis (systemic mast cell disease) can have signs and symptoms related to involvement of the hematopoietic system, the gastrointestinal (GI) tract, the skin, and the immune system. Additional coexistent hematologic disorders may also be a source of clinical manifestations. Systemic mastocytosis is known to be associated with a number of other hematologic diseases, including the following:

The incidence of various symptoms reported in one of the largest case series of systemic mastocytosis is as follows [9] :

  • GI symptoms - 65%
  • Cutaneous symptoms - 53%
  • Mediator-related symptoms - 47%
  • Constitutional complaints - 42%
  • Urticaria pigmentosa - 41%
  • Musculoskeletal symptoms - 31%
  • Idiopathic and/or recurrent anaphylactoid reactions - 17%

Many GI manifestations are observed in patients with systemic mastocytosis. Abdominal pain is the most common GI symptom, followed, by diarrhea, nausea, and vomiting. Symptoms and signs of gastroesophageal reflux disease (GERD) and malabsorption are noted in some patients. Duodenal ulceration and severe duodenitis is seen in 30% to 50% of untreated cases. [24]

Some studies show precipitation of GI manifestations by agents such as penicillin, narcotics, cocaine, aspirin, [27] nonsteroidal anti-inflammatory drugs (NSAIDs), and dipyridamole (Persantine). These drugs can also provoke anaphylaxis, vascular collapse, or syncope.

Pruritus seem to be as common as GI complaints in patients with systemic mastocytosis. Patients may present with pruritus and flushing if their mastocytosis is associated with cutaneous abnormalities.

While the risk of recurrent anaphylactoid reaction is well known, it appears that the association with Hymenoptera (eg, bee, wasp) stings is stronger than the association with other food- and drug-induced systemic reactions. [5]

Caution during anesthesia in the endoscopic and surgical suites is advised. Rare anaphylactoid reactions to intravenous contrast have been reported. [6]

Anemia and coagulopathy (eg, acquired von Willebrand syndrome [28] ) may be observed.



Physical examination findings in patients with systemic mastocytosis (systemic mast cell disease) may include the following:

  • Signs of anemia, such as pallor, can be noted in some patients.

  • Hepatomegaly (27%), splenomegaly (37%), and lymphadenopathy (21%) can be found in adult patients. [9]

  • GI bleeding may be present; contributing factors may include thrombocytopenia caused by splenomegaly, hypersplenism, and a rise in portal pressure; heparin release from mucosal mast cells; and vitamin K malabsorption resulting from mast cell involvement.

  • Patients may have signs of urticaria (41%) if the mastocytosis is associated with cutaneous involvement; in these situations, flushing can be noted upon physical examination.

  • Osteolysis and pathological fractures are rarely noted (7%).



Mutations of the c-kit proto-oncogene may cause some forms of mastocytosis. [29, 30, 21] Mutations of c-kit in mast cell tumor lines and the ability of c-kit to cause mast cell proliferation and transformation suggest that these mutations are necessary in most forms of mastocytosis.

Several types of somatic activating and nonactivating mutations in c-kit have been demonstrated to cause systemic mastocytosis. One of the common mutations found in systemic mastocytosis is an exon 17 D816V KIT receptor mutation. Most, if not all, adult patients with systemic mastocytosis carry this mutation. [31] In the majority of patients, mastocytosis does not appear to be inherited, but rare familial cases with KIT mutations have been reported.