Case report: Diagnosis of acute monocytic leukaemia (AML-M5b) in a juvenile cat

摘要

A six month old male domestic cat was presented with severe exhaustion, fatigue and a history of previous treatments for weakness, depression, decrease appetite, cough, purulent and bloody nasal discharge for two months. The main clinical signs were dehydration, pale mucous membranes, submandibular lymphadenopathy and respiratory distress. Haematology showed macrocytic anaemia, leukopenia and thrombocytopenia coupled to the presence of 20% of monocyte precursors with dysplastic morphologies. Feline leukaemia virus antigen and Mycoplasma hemofelis was detected. Bone marrow examination revealed increased myeloid to erythroid ratio and the presence of 35.8% of monoblasts and promonocytes with 9.7% of monoblasts. Furthermore, the neoplastic cells were positive by alpha-Naphthyl Butyrase Esterase stain, but negative for Myeloperoxidase and Sudan Black B. Histopathological findings consisted in infiltration of liver, spleen, lymph nodes and lungs by neoplastic cells. The final diagnosis of acute monocytic leukaemia (AML-M5b) was made.