Aggressive systemic mastocytosis presenting with hepatic cholestasis.

Systemic mastocytosis results in the accumulation of mast cells in various tissues. We report a rare case of systemic mastocytosis presenting with cholestatic liver disease. Our patient was a 60-year-old African-American woman who presented with diarrhea, weight loss, hepatosplenomegaly and cholestatic pattern of serum liver chemistry tests. Immunohistological stains with mast-cell tryptase and CD117 antibodies performed on the liver-biopsy tissue showed prominent mast cells. Subsequently, bone-marrow biopsy and small-bowel biopsies also showed mast-cell infiltration confirming the diagnosis of systemic mastocytosis. The patient underwent treatment with imatinib mesylate without response. Her disease transformed into acute myeloid leukemia and she ultimately died from sepsis. This case underscores the importance of including rare conditions like systemic mastocytosis in the differential diagnosis of cholestatic disorders.