Thymic Cystic Degeneration, Pseudoepitheliomatous Hyperplasia, and Hemorrhage in a Dog with Brodifacoum Toxicosis

Thymic cysts with pseudoepitheliomatous hyperplasia are described in a 7-month-old female American Eskimo Dog that died of complications from brodifacoum poisoning. Grossly, there was hemothorax with marked cranial mediastinal hemorrhage. Histologically, thymic lobules were expanded and distorted by...

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Bibliographic Details
Published in:Veterinary Pathology
Main Authors: Rickman, B. H., Gurfield, N.
Format: Article in Journal/Newspaper
Language:English
Published: SAGE Publications 2009
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Online Access:http://dx.doi.org/10.1354/vp.08-vp-0193-r-bc
http://journals.sagepub.com/doi/pdf/10.1354/vp.08-VP-0193-R-BC
http://journals.sagepub.com/doi/full-xml/10.1354/vp.08-VP-0193-R-BC
Description
Summary:Thymic cysts with pseudoepitheliomatous hyperplasia are described in a 7-month-old female American Eskimo Dog that died of complications from brodifacoum poisoning. Grossly, there was hemothorax with marked cranial mediastinal hemorrhage. Histologically, thymic lobules were expanded and distorted by irregular cysts, lined by single to multiple layers of plump to slightly attenuated polygonal squamous epithelial cells supported by a basement membrane (pseudoepitheliomatous hyperplasia). The thymus had a paucity of lymphocytes and lacked corticomedullary differentiation. Extensive hemorrhage within the cysts and thymic parenchyma extended into the adjacent adipose tissue. To the authors' knowledge, this is the first report of cystic thymic degeneration with pseudoepitheliomatous hyperplasia in a nonhuman species.