Systemic mastocytosis with portal hypertension. Autopsy findings and ultrastructural study of the liver.

Systemic mastocytosis is a rare cause of portal hypertension with only two previously reported cases to our knowledge. A 51-year-old man who was seen with intractable diarrhea and abdominal distention was found to have this combination at autopsy. At autopsy the liver showed bridging portal fibrosis. Subendothelial collagen deposition was demonstrated ultrastructurally. We present the possible mechanisms of portal hypertension in systemic mastocytosis.