A 59-year-old lady with a 20-year history of systemic mastocytosis. Axial contrast-enhanced CT demonstrates hepatomegaly and a large heterogeneous mass with areas of arterial enhancement and heterogeneous hypoattenuating apperance on portal venous phase (circled), increased retraction of the hepatic capsule related to volume loss (arrowhead), and an abnormal heterogenous appearance of the spleen with surronding ring of hypoattenuating soft tissue (white arrows).