CORRELATION OF ULTRASOUND FINDINGS, LIVER AND SPLEEN CYTOLOGY, AND PROGNOSIS IN THE CLINICAL STAGING OF HIGH METASTATIC RISK CANINE MAST CELL TUMORS

Authors


  • This work was performed at Washington State University, Veterinary Teaching Hospital, Pullman, WA.

  • Portions of the work were presented at: the 2008 Annual Scientific Meetings Proceedings, October 20–25, 2008, San Antonio, TX, p. 80; and at the ESVONC Spring Congress, March 27–29, 2009, Visegrad, Hungary, p. 26.

  • >This work was not supported by a grant.

Address correspondence and reprint requests to Janean Fidel at the above address. E-mail: jfidel@vetmed.wsu.edu

Abstract

Cytologic sampling of the ultrasonographically normal spleen and liver is not implemented routinely in the clinical staging of canine cutaneous mast cell tumors and normal ultrasound findings are often accepted as sufficient evidence for ruling out splenic or liver metastasis. Our objective was to define the specificity and sensitivity of ultrasound findings for diagnosis of mast cell infiltration when verified with cytologic evaluation, and to define the prognostic role of cytologic evaluation of liver and splenic aspirates. Dogs with a diagnosis of clinically aggressive grade II, or grade III mast cell tumor treated with a combination vinblastine/CCNU chemotherapy protocol, were selected retrospectively based on availability of cytologic evaluation of spleen plus or minus liver for staging. Out of 19 dogs, 10 dogs had a grade II tumor and nine a grade III tumor. Seven dogs had mast cell infiltration of the spleen, liver, or both. The sensitivity of ultrasound for detecting mast cell infiltration was 43% for the spleen and 0% for the liver. Dogs with positive cytologic evidence of mast cell infiltration to spleen, liver, or both had significantly shorter survival (100 vs. 291 days) than dogs without evidence of mast cell infiltration (P<0.0001). Routine splenic aspiration should be performed regardless of ultrasonographic appearance in dogs with a clinically aggressive mast cell tumor.

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