Granular cell tumor in a lumbar spinal nerve of a dog.
A 2-year-old Great Dane dog with a 2.5-week history of progressive paraparesis was presented to the Veterinary Medical Teaching Hospital at the University of Wisconsin-Madison. Neurologic examination revealed nonambulatory paraparesis with reduced to absent withdrawal hind-limb reflexes and lumbar pain. Magnetic resonance imaging and gross pathology confirmed a larger regional lumbar mass and a second smaller extradural mass within the spinal canal. The left lumbar mass was associated with extensive hemorrhage; dissection showed a dark-red, soft, well-circumscribed mass measuring 2 cm x 1.5 cm x 0.5 cm within the left fourth lumbar spinal nerve. Histopathological evaluation with immunohistochemistry revealed sheets of round to polygonal cells with diffuse granular cytoplasm demonstrating diastase-resistant periodic acid-Schiff reactivity and positive immunoexpression of S100 and neuron-specific enolase. The smaller extradural mass within the spinal canal exhibited similar morphology. Based on gross, histological, and immunohistochemical evidence, the masses were diagnosed as granular cell tumor.
Rao
Deepa
D
Veterinary Medical Teaching Hospital, University of Wisconsin, Madison, WI, USA. raod2@niehs.nih.gov
Rylander
Helena
H
Drees
Randi
R
Schwarz
Tobias
T
Steinberg
Howard
H
D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D004285:Dogs; D016586:Granular Cell Tumor / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000662:veterinary*; D008161:Lumbosacral Region; D008297:Male; D011859:Radiography; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000662:veterinary*; D013127:Spinal Nerves / Q000473:pathology*