Article Text

Paraneoplastic immune-mediated neutropenia in a dog following thymoma excision with later development of metastatic thymic carcinoma treated with toceranib phosphate
  1. Erin O'Connell,
  2. Aaron Harper,
  3. Richard Blundell and
  4. Daniel Batchelor
  1. Small Animal Clinical Science, University of Liverpool Small Animal Teaching Hospital, Neston, UK
  1. Correspondence to Erin O'Connell; Erin.Oconnell{at}LIVERPOOL.AC.UK


A thymoma was an incidental finding in a seven-year-old, female neutered, crossbred dog referred for an acute hepatopathy. Excision of the thymoma was performed via median sternotomy, and 11 weeks later the dog presented with severe neutropenia. The bone marrow was hypercellular, and paraneoplastic immune-mediated neutropenia was diagnosed following exclusion of other causes. The neutrophil count increased to normal within seven days of treatment with prednisolone, which was subsequently tapered. A caudal mediastinal mass was documented 17 months following initial thymoma excision, and pleural and mediastinal metastases were evident on CT. Cytology was consistent with carcinoma. Following the prescription of toceranib phosphate, there was stable disease on CT at eight weeks and six months. At 12 months there was severe locoregional progression and the dog died nine days thereafter. Postmortem examination showed diffuse metastatic carcinoma of the caudal mediastinum, parietal pleura and diaphragm, and histopathology/immunohistochemistry was most consistent with thymic carcinoma.

  • thymoma
  • thymic carcinoma
  • immune mediated neutropenia
  • toceranib phosphate

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  • Contributors EO was the primary clinician during treatment of the case and drafted the article for publication. AH provided critical revision of the article. RB performed the post-mortem examination and approved the report of this for publication; four figures were also provided for the article. DB was a supervising clinician during treatment of the case and critically revised and approved the article for publication.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests AH is on the editorial board for Veterinary Record Case Reports.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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