Multicentric Benign Peripheral Nerve Sheath Tumors in Two Related Bearded Dragons, Pogona vitticeps

Abstract

Multiple subcutaneous masses from two sibling bearded dragons were removed. Nodules were well demarcated, restricted to the subcutis, and soft, white to yellow, resembling adipose tissue. Histologically, the masses were composed of short interlacing streams and bundles of spindle cells, with regions of vague nuclear palisading. Two of the tumors contained a subpopulation of polygonal cells with abundant periodic acid-Schiff (PAS)-positive cytoplasmic granules. Neoplastic cells were immunohistochemically positive for S100 and neuron-specific enolase (NSE) but negative for desmin and smooth muscle actin. Electron microscopy and reticulin stains demonstrated a continuous basal lamina separating intertwining cells. Histologic, ultrastructural, and immunohistochemical features were consistent with a peripheral nerve sheath origin. At 1 year postexcision, local reoccurrence of a single incompletely excised mass from the left shoulder was noted.