[Systemic mastocytosis: case report with literature review]

Mastocytosis is a clonal neoplastic disorder of the mast cells. The clinical signs and symptoms of mastocytosis are heterogeneous ranging from indolent disease with a long-term survival to a highly aggressive neoplasm with survival of about 6 months. Systemic mastocytosis (SM) is characterized by mastocyte infiltration of one or more organs, with or without skin involvment.

The presented patient presents a highly challenging diagnostic and therapeutic case. A 46-year-old man was referred to our Centre due to the 7-year-long history of hepatosplenomegaly and mild thrombocytopenia. Ultrasound examination showed hepatosplenomegaly (liver 170 mm; spleen 200 mm), platelet count was 90 x 10(9)/L, serum tryptase level was elevated and bone marrow biopsy showed infiltration with mast cells (CD117, CD25 and mast cell tryptase positive). Our patient was diagnosed with aggressive systemic mastocytosis (SM) according to WHO Classification (2008), although the clinical course of the disease was indolent, without complications for more than 7 years. Because of the 'intermediate' course, this patient was referred to as smouldering or intermediate SM and was not treated with cytostatics.

Utilizing the established criteria, indolent SM can be discriminated from the aggressive subvariants of SM in most cases. However, a small group of patients, like our case belongs to the "grey zone". Therapeutic approach to these patients is individual and prognosis is uncertain.