1. A patient with splenic mastocytosis who had hypersplenism, periodic flushing and clotting defects is presented.
2. A correlation is shown between mastocytosis and elevated histamine and heparin levels in the spleen.
3. The patient is well nine months after splenectomy.
4. Wright’s stain or polychrome methylene blue stain of splenic tissue imprints is recommended as a method of demonstrating mast cells in the spleen.
5. Mast cell counts of normal spleen showed 0 to 0.25% of nucleated cells on imprint.
6. Splenic aspiration stained with Wright’s stain is satisfactory for demonstrating mastocytosis, though not dependable for true mast cell counts.
7. Cases of primary hypersplenism should routinely be reviewed for splenic mastocytosis.
8. Splenic mastocytosis is a variant of systemic mast cell disease in which involvement is predominately confined to the spleen.