An exophytic multinodular chordoma of the cervical spine in a ferret

An 8-year-old male ferret was presented with dyspnea and large, palpable cervical masses. Pathological examination revealed multiple exophytic nodular masses arising from the atlas and axis. Those vertebrae were almost completely replaced by neoplastic tissue. Histologically, the masses were composed of physaliferous cells with foamy cytoplasm embedded within a prominent chondro-osseous matrix. The diagnosis of chordoma was confirmed by immunohistochemistry, as tumor cells were positive for pan-cytokeratin, vimentin, S-100, and neuron-specific enolase. Notably, some chondrocytes and osteocytes adjacent to the tumor cells also expressed these markers, suggesting a neoplastic origin rather than a reactive process. Ki-67 labeling was confined to a subset of cytokeratin-positive cells at the periphery of the nodules, indicating that peripheral proliferation contributes to the exophytic growth pattern. This report describes a case of cervical chordoma with a unique exophytic presentation in a ferret.