Primitive neuroectodermal tumor in the cervical spine of a dog - Case Report

A case of peripheral primitive neuroectodermal tumor in the cervical region of a canine is described. The patient was a canine, male, five years old, large size, with acute neurological clinical signs, severe neck pain and tetraplegia. On computed tomography, an oval-shaped mass located dorsally to cervical vertebrae C4 to C7 was observed, with infiltration over the spinal cord between vertebrae C4 and C5, discreetly widening the dorsal intervertebral foramina of the cervical vertebrae and compressing the dorsal portion of the spinal cord of this segment. Under microscopy, the neoplastic cells were small, irregular in shape and with scarce cytoplasm. Immunoreactivity for vimentin, which can only be expressed in PTNEs tumors, was decisive for diagnostic confirmation. Additionally, the positivity of the S-100 protein, which is expressed in neuroectodermal cells mainly of the neural crest cells, reinforced the classification as PTNE, and the negativity in the expression for glial fibrillary acidic protein (GFAP) ruled out the presence of small cell glioma of the central nervous system. Based on the clinical history, imaging exams, cellular morphology and mainly on immunohistochemical staining, the diagnosis of primitive neuroectodermal tumor (PTNE) with infiltration and compression of the spinal cord in the cervical region of the dog was confirmed, considered uncommon in this species.