Systemic mastocytosis with normal serum tryptase

Systemic mastocytosis (SM) is a rare disease which is characterized by the accumulation of mast cells in >1 extra-cutaneous organ, most often the bone marrow. In the majority of patients, the activating D816V mutation in KIT induces increased proliferation and survival in the neoplastic mast cells. The WHO has formulated criteria for the diagnosis of SM: Most criteria can usually only be obtained by bone marrow (BM) aspiration and biopsy. Due to the heterogeneous clinical picture of SM, it can be challenging to determine when BM examination is indicated. Serum tryptase is often used as a screening tool for SM. For more information click here.