Marked cytoreduction of a lymphocyte-rich mediastinal thymoma with neoadjuvant chemotherapy in a cat. Issue 1 (22nd May 2015)

• Record Type: Journal Article
• Authors: Tong, Linda J; Hosgood, Giselle; Labruyère, Julien; Bennett, Susan L; FitzGerald, Louise; Shiel, Robert E
• Is Part Of: Journal of feline medicine and surgery open reports. Volume 1:Issue 1(2015)
• Publication Date: 2015-05-22
• Subjects: Cats -- Diseases -- Periodicals; Cats -- Surgery -- Periodicals; 636.8089
• DOI: 10.1177/2055116915585024
• Languages: English
• ISSNs: 2055-1169

Abstract

Case summary: A 15-year-old neutered female domestic shorthair cat presented with lethargy and acute-onset dyspnoea. Thoracic computed tomography (CT) revealed a large, cranial mediastinal mass with an estimated volume of 180.7 cm 3 . Chemotherapy consisting of dexamethasone followed by L-asparaginase, prednisolone, vincristine and doxorubicin was commenced owing to the severity of disease and initial possibility of lymphoma. A diagnosis of lymphocyte-rich thymoma was made based upon histological examination, positive pancytokeratin staining, variable lymphocyte CD3 expression and T cell receptor gamma polyclonality. Thoracic CT performed 35 days after the commencement of chemotherapy showed a marked reduction in the size of the mass, with an estimated volume of 9.4 cm 3 . A median sternotomy and thymectomy were performed. No clinical signs have recurred 34 months after surgery. Conclusions and relevance: The response to chemotherapy in this case was unusual, and is likely associated with the high non-neoplastic lymphoid component of the mass. The case demonstrates that preoperative chemotherapy can be used to reduce thymoma volume prior to surgery, potentially decreasing anaesthetic risk.