Splenic Hemangiosarcoma in a cat:
History: A 13 year old cat was was diagnosed with anemia and an abdominal mass. A fine needle aspirate cytology was consistent with a mesenchymal neoplasia.
Spleen: There are broad sheets of large numbers of polygonal to round cells with abundant eosinophilic cytoplasm that occasionally form blood filled channels. Nuclei are polygonal with dispersed chromatin and single eosinophilic nucleoli. There are large multifocal to coalescing areas of necrosis in the spleen with numerous accumulations of intracellular and extracellular hemosiderin. Many neoplastic cells contain large intracytoplasmic lipid vacuoles. There are occasional multinucleated giant cells. There are 35 mitotic figures in 10 random 400x fields. There is moderate anisocytosis and anisokaryosis with occasional bizarre mitotic figures and individual cell necrosis. There is mild extramedullary hematopoiesis.
Morphologic diagnosis: Spleen, hemangiosarcoma