ABSTRACT

An adult bearded dragon, Pogona vitticeps, presented with an unresectable axillary mass. The animal deteriorated rapidly and was euthanized. Numerous metastases were present in the liver, heart, and lungs. Histologically, the tumor was composed of tightly packed streaming bundles of plump cells which were enmeshed in a delicate network of reticulin. Neoplastic cells were positive for vimentin, but were negative for desmin, smooth muscle actin, and S-l00a via immunohistochemistry. Ultrastructurally, neoplastic cells exhibited numerous inter-digitating cytoplasmic processes, and were individually surrounded by a discontinuous basement membrane. These features are diagnostic for a malignant peripheral nerve sheath tumor. This is the first report of a malignant peripheral nerve sheath tumor in a saurian.