Extreme neutrophilic leucocytosis and intrathoracic mass in a Fox Terrier (abstract)

Authors: Squires RA, Thompson KG
Publication: New Zealand Veterinary Journal, Volume 52, Issue 1, pp 50, Feb 2004
Publisher: Taylor and Francis

Animal type: Companion animal, Dog
Subject Terms: Alimentary system/gastroenterology, Nutrition/metabolism, Wasting disease/disorder, Clinical pathology, Diagnostic procedures, Pathology
Article class: Abstract

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Abstract: An 8-year-old female Fox Terrier was presented for acute anorexia and depression. A haemogram revealed extreme neutrophilic leucocytosis (136x10⁹/L neutrophils). By Day 4, the neutrophilia was more marked (214x10⁹/L segmented; 23x10⁹/L band). Imaging revealed a cranial mediastinal mass, pleural effusion and small pneumothorax. Needle aspiration of the mass showed cells resembling malignant histiocytes against a background of mature neutrophils. On Day 7, the mass was surgically removed. Histologically, it revealed a malignancy suggestive of histiocytic sarcoma intensely infiltrated with neutrophils. Immunocytochemical investigations are pending. Post-operatively, the dog’s appetite and demeanour improved but breathing was laboured, and neutrophilia persisted (300x10⁹/L on Day 14). The dog was humanely killed on Day 14; post mortem examination revealed no distant metastases. This dog’s illness is strongly reminiscent of a rare human condition, inflammatory malignant fibrous histiocytoma with leukaemoid reaction (IMFH-LR). In IMFH-LR, neoplastic cells produce cytokines that attract neutrophils to the tumour. Other cytokines stimulate the bone marrow to produce extreme neutrophilia. Although paraneoplastic neutrophilia has previously been described in dogs, this is an extreme example and the condition has not previously been associated with histiocytic or intrathoracic malignancies.

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