Suspected metastatic coccygeal chordoma in a ferret (Mustela putorius furo).

A chordoma was removed from the tail base of a 6.5-year-old ferret (Mustela putorius furo). A nodule was observed in the area of tumor development when the ferret was purchased at 3 months of age. Although the nodule did not enlarge for 2 years, slow, steady growth of the tumor was observed for 4 years before surgical removal. Eight months after removal of the chordoma, the ferret developed 2 cutaneous masses. One was adjacent to the vulva, close to where the chordoma had been removed from, whereas the other was in the nasofacial region. After 4 months of slow growth, both masses were removed and both were histologically and immunohistochemically consistent with chordoma. Over the next 8 weeks, additional masses developed in the facial, maxillary gingival, and scapular regions. Enlargement of the gingival mass caused dysphagia, and the ferret was euthanized. Although a necropsy was not performed, these additional masses had a clinical appearance and texture that was similar to the 2 previously removed cutaneous chordomas. To the authors' knowledge, this is the first report of a ferret coccygeal chordoma that developed close to the base of the tail. Ferret chordomas have been reported previously to metastasize to the subcutis overlying the tumor. However, this is the first report of a ferret chordoma that metastasized to a location distant to the primary site of neoplasm development. Cell proliferation indices did not predict this metastatic behavior. It is hypothesized that the long clinical period before removal may have predisposed this neoplasm to metastasis. Observations from this case suggest that chordomas in ferrets may have metastatic potential and so should be removed promptly.