Systemic Mastocytosis : Spleen
Image Description
Splenic involvement is seen in about 50% of cases of systemic mastocytosis. Depending upon the degree of involvement, there may be massive splenomegaly, especially in aggressive forms such as aggressive systemic mastocytosis and systemic mastocytosis with an associated hematologic neoplasm. Rare cases show isolated splenic involvement with signs of hypersplenism.
Grossly, the splenic capsule is thickened due to fibrosis. The cut surface often shows multiple 1-2 mm nodular areas scattered throughout the organ. Microscopically, these lesions correspond to mast cell infiltrares that are evenly distributed between both red and white pulp areas and often have a granulomatous appearance.
Case History: The patient was an adult female who presented with skin lesions, flushing, and diarrhea and was found to have hepatosplenomegaly, anemia, and thrombocytopenia. Splenectomy specimen showed prominent follicles. Flow cytometry was positive for CD2, CD9, CD25, CD68, CD117, and tryptase; Negative markers included CD3, CD4, CD20, and CD34. The final diagnosis was systemic mastocytosis. The image shows fibrotic areas with a granulomatous appearance containing spindled and round mast cells as well as eosinophils and plasma cells (see higher magnification in slide 50).
Grossly, the splenic capsule is thickened due to fibrosis. The cut surface often shows multiple 1-2 mm nodular areas scattered throughout the organ. Microscopically, these lesions correspond to mast cell infiltrares that are evenly distributed between both red and white pulp areas and often have a granulomatous appearance.
Case History: The patient was an adult female who presented with skin lesions, flushing, and diarrhea and was found to have hepatosplenomegaly, anemia, and thrombocytopenia. Splenectomy specimen showed prominent follicles. Flow cytometry was positive for CD2, CD9, CD25, CD68, CD117, and tryptase; Negative markers included CD3, CD4, CD20, and CD34. The final diagnosis was systemic mastocytosis. The image shows fibrotic areas with a granulomatous appearance containing spindled and round mast cells as well as eosinophils and plasma cells (see higher magnification in slide 50).