Malignant peripheral nerve sheath tumor in a hamster.

An adult female golden hamster (Mesocricetus auratus) developed a firm subcutaneous mass on the lateral distal right forelimb that progressed to diffuse limb enlargement accompanied by extensive cutaneous ulceration and drainage and axillary lymph node metastasis. Touch imprint cytology revealed pleomorphic neoplastic mesenchymal cells. On histology, the invasive neoplasm merged with a large subcutaneous nerve and was composed of spindle cells with a high mitotic index, and lymph node metastasis was confirmed. Histologic morphology and positive immunohistochemical staining of neoplastic cells for vimentin, S100, and neuron-specific enolase were consistent with a malignant peripheral nerve sheath tumor. Although relatively common in dogs, peripheral nerve sheath tumors had not been reported previously in hamsters.