Introduction:
Systemic Mastocytosis (SM) is a rare disorder in which mast cells
pathologically accumulate within tissue. The mast cells can be limited
to the skin, or they can be systemic and involve extracutaneous tissues.
One subtype of systemic mastocytosis (SM) is called indolent systemic
mastocytosis, which is considered a less aggressive form of the disease,
compared to advanced systemic mastocytosis which is considered to have
organ impairment due to mast cell infiltration. Multi-kinase inhibitors
such as Midostaurin and Imatinib are often used in the treatment of
advanced SM or indolent SM that is refractory to conservative
symptomatic treatment, but currently Avapritinib is reserved for
treatment of advanced SM. Here is a case of an indolent SM responding to
treatment with lower dose Avapritinib.