Systemic Mastocytosis : Spleen
Image Description
Splenic Involvement in Systemic Mastocytosis: Mast cells are virtually absent in normal and reactive spleen. Therefore, an increased number of mast cells in the form of clusters or large infiltrates is diagnostic of splenic involvement in systemic mastocytosis. Mast cell infiltrares are evenly distributed between both red and white pulp and often have a granulomatous appearance.
Other findings in the spleen include: reticulin and collagen fibrosis, a reactive increase in eosinophils and plasma cells, and extramedullary hematopoiesis.
Differential Diagnosis: Mast cell infiltrates in spleen may be confused with T-cell lymphoma, follicular hyperplasia or lymphoma, Kaposi sarcoma, hairy cell leukemia, myeloproliferative disorder, or a granulomatous process.
The image shows fibrotic, granuloma-like nodules centered around blood vessels. They contain a mixed infiltrate of spindled and round mast cells as well as eosinophils and plasma cells (see higher magnification in slide 50).
Other findings in the spleen include: reticulin and collagen fibrosis, a reactive increase in eosinophils and plasma cells, and extramedullary hematopoiesis.
Differential Diagnosis: Mast cell infiltrates in spleen may be confused with T-cell lymphoma, follicular hyperplasia or lymphoma, Kaposi sarcoma, hairy cell leukemia, myeloproliferative disorder, or a granulomatous process.
The image shows fibrotic, granuloma-like nodules centered around blood vessels. They contain a mixed infiltrate of spindled and round mast cells as well as eosinophils and plasma cells (see higher magnification in slide 50).