Paraneoplastic leukocytosis in a dog following liposarcoma resection

A 10-year-old, female, neutered cocker spaniel presented for surgical debulking of an axillary and cranial thoracic wall liposarcoma. Pre-surgical blood analysis demonstrated anaemia (packed cell volume 17%), leukocytosis (white blood cell count 43.95 × 10 ⁹/L) and thrombocytopenia (15 × 10 ⁹/L), with platelet loss secondary to chronic intra-lesional haemorrhage or immune-mediated destruction, and concomitant Staphylococcus pseudintermedius urinary tract infection. A blood transfusion and antibiotics were administered before surgery. Within 48 hours after surgery, an extreme leukocytosis (white blood cell count 170 × 10 ⁹/L), involving a severe left shift neutrophilia (95 × 10 ⁹/L) was observed; this resolved within 10 days. Serum granulocyte-colony stimulating factor levels were similar to controls. The extreme leukocytosis was suspected to be related to a paraneoplastic leukaemoid reaction combined with an expected postoperative mild leukocytosis. Further investigation into the pathophysiology underlying similar cases is required. One month after surgery, all haematological abnormalities had normalised, and metronomic chemotherapy with chlorambucil commenced.