In systemic mastocytosis the liver, spleen, and lymph nodes may be infiltrated by mast cells, with patterns of infiltration specific for each tissue. This may result in hepatosplenomegaly and enlarged lymph nodes. Extensive involvement with mast cells may also be associated with organ dysfunction. Specifically, in the case of liver, mast cell infiltration may result in fibrosis, portal hypertension, and abdominal ascites. Clinically significant involvement of the liver, spleen, and lymph nodes appears to be more common in patients with aggressive forms of mastocytosis, including those with a hematologic disorder.