ABSTRACT
Hepatic encephalopathy has been listed as a differential for llamas displaying neurologic signs, but it has not been histopathologically described. This report details the neurologic histopathologic findings associated with 3 cases of hepatic lipidosis with concurrent neurologic signs and compares them to 3 cases of hepatic lipidosis in the absence of neurologic signs and 3 cases without hepatic lipidosis. Brain from all 3 llamas displaying neurologic signs contained Alzheimer type II cells, which were not detected in either subset of llamas without neurologic signs. Astrocytic immunohistochemical staining intensity for glial fibrillary acid protein was decreased in llamas with neurologic signs as compared to 2 of 3 llamas with hepatic lipidosis and without neurologic signs and to 2 of 3 llamas without hepatic lipidosis. Immunohistochemical staining for S100 did not vary between groups. These findings suggest that hepatic encephalopathy may be associated with hepatic lipidosis in llamas.
Subject(s)
Camelids, New World , Fatty Liver/veterinary , Hepatic Encephalopathy/veterinary , Lipidoses/veterinary , Animals , Astrocytes/metabolism , Brain/pathology , Diagnosis, Differential , Fatty Liver/pathology , Female , Glial Fibrillary Acidic Protein/metabolism , Hepatic Encephalopathy/pathology , Immunohistochemistry/veterinary , Lipidoses/pathology , Male , Retrospective Studies , S100 Proteins/metabolismABSTRACT
Lymphoma is the most common malignant neoplasm in the horse. Single case reports and small retrospective studies of equine lymphomas are reported infrequently in the literature. A wide range of clinical presentations, tumor subtypes, and outcomes have been described, and the diversity of the results demonstrates the need to better define lymphomas in horses. As part of an initiative of the Veterinary Cooperative Oncology Group, 203 cases of equine lymphoma have been gathered from 8 institutions. Hematoxylin and eosin slides from each case were reviewed and 187 cases were immunophenotyped and categorized according to the World Health Organization classification system. Data regarding signalment, clinical presentation, and tumor topography were also examined. Ages ranged from 2 months to 31 years (mean, 10.7 years). Twenty-four breeds were represented; Quarterhorses were the most common breed (n = 55), followed by Thoroughbreds (n = 33) and Standardbreds (n = 30). Lymphomas were categorized into 13 anatomic sites. Multicentric lymphomas were common (n = 83), as were skin (n = 38) and gastrointestinal tract (n = 24). A total of 14 lymphoma subtypes were identified. T-cell-rich large B-cell lymphomas were the most common subtype, diagnosed in 87 horses. Peripheral T-cell lymphomas (n = 45) and diffuse large B-cell lymphomas (n = 26) were also frequently diagnosed.