MALIGNANT HISTIOCYTOSIS IN A CAT

A 13-year-old male domestic shorthair cat was found to have normocytic hypochromic regenerative anemia, lymphopenia, eosinopenia, thrombocyt openia, hyperglycemia, hyperbilirubinemia, and a prolonged activated p artial thromboplastin time. Transfusions of packed RBC failed to maint ain the PCV above 13% for > 8 hours. The cat was euthanatized. At necr opsy, the spleen, liver, lymph nodes, and bone marrow were infiltrated with malignant histiocytes undergoing erythrophagocytosis.