Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
Section of Anatomic Pathology, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
J Vet Diagn Invest. 2022 Nov;34(6):1010-1014. doi: 10.1177/10406387221120672. Epub 2022 Aug 22.
An 8-y-old Labrador Retriever dog had mild ataxia of the hindlimbs 4 mo after lumbosacral dorsal laminectomy for intervertebral disk disease. Ataxia of the hindlimbs gradually worsened over the next 6 y. On autopsy, gross lesions were not recognized in the spinal cord. Histopathology revealed an intradural extraparenchymal cholesterol granuloma in the cauda equina associated with remnant nerve roots. Nerves associated with the cholesterol granuloma had axonal degeneration, myelin vacuolation, and edema. In those foci, macrophages were increased in number between nerve fibers. Immunohistochemistry for neurofilament protein and Luxol fast blue staining highlighted the presence of remnant axons and myelin sheaths within the granuloma. Inflammatory cell infiltrates in the granuloma were mainly macrophages and CD3- or CD20-immunopositive T or B lymphocytes, respectively. We conclude that the cholesterol granuloma likely formed subsequent to degenerative neuropathy in the cauda equina.
一只 8 岁的拉布拉多猎犬在因椎间盘疾病行腰骶部背侧椎板切除术 4 个月后出现后肢轻度共济失调。后肢共济失调在接下来的 6 年中逐渐恶化。尸检时，脊髓未发现明显病变。组织病理学显示马尾脊硬膜外有硬膜内上皮下胆固醇肉芽肿，伴有残留神经根。与胆固醇肉芽肿相关的神经有轴突变性、髓鞘空泡形成和水肿。在这些病灶中，神经纤维之间的巨噬细胞数量增加。神经丝蛋白免疫组化和卢索快速蓝染色突出显示了肉芽肿内残留轴突和髓鞘套的存在。肉芽肿中的炎症细胞浸润主要是巨噬细胞和 CD3 或 CD20 免疫阳性的 T 或 B 淋巴细胞。我们得出结论，胆固醇肉芽肿可能是马尾神经退行性病变后形成的。
