A retrospective study of prognostic factors in 29 dogs with surgically treated thymic epithelial tumors

Thymic epithelial tumors (TETs) are a rare type of tumor that occur in the anterior mediastinum. The biological behavior of these tumors and the prognostic factors in dogs remain unclear. Although several studies have suggested that clinical staging (Masaoka classification) is related to prognosis, the prognostic significance of histological subtypes (WHO classification) and paraneoplastic syndromes remains controversial. The objective of this study was to investigate whether paraneoplastic syndromes, Masaoka classification, and WHO classification are associated with the prognosis of canine TET. Hypercalcemia and anemia were observed as paraneoplastic syndromes in the 29 dogs included in this study. The presence of hypercalcemia did not result in a statistical difference in median survival time. Anemia could not be statistically analyzed due to the small number of cases. Our results suggest that the WHO classification, like the Masaoka classification, may also be useful for predicting the prognosis of canine TET.