Pathology of the urinary system

5a) Renal cysts, single or multiple

  

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can be found in all species but are most common in pigs and calves; 

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may result from: 

        -  anomaly of development or renewal of the tubular basement membrane, resulting in the 

formation of diverticula; 

        -  disordered growth of tubular epithelial cells, leading to focal hyperplastic and cystic lesions; 

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cysts of variable size, usually 1-2 cm in diameter, are typically filled with fluid and lined by 

attenuated epithelium; 

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lesions can be uni- or bilateral and are most often just an incidental finding in animals; 

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grossly, kidneys contain one, few or many cysts in both cortex and medulla; 

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on cut surface, severely affected kidneys have a "honeycomb" appearance; 

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consequences:   - cysts may remain static or may enlarge slowly or increase in number; 

 

 

 

  - progressive loss of renal tissue by compressive atrophy; 

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can also be acquired: obstruction of tubules by accumulation of fibrous tissue in chronic renal 

disease or in dysplasia; a common manifestation of renal dysplasia in humans;