This is Learning Component 6 in Learning Module 1. We will show examples of features ( things ) including mineral deposits, urates, pigments, dust,

Transcription

1 This is Learning Component 6 in Learning Module 1. We will show examples of features ( things ) including mineral deposits, urates, pigments, dust, plant material, and amyloid. 1

2 Calcium salts are the most common mineral deposited in avian tissues. They may form in damaged or necrotic tissue (dystrophic calcification), or when calcium reaches excessive blood levels as can occur in renal failure and in birds fed high calcium diets, such as broiler breeder hens or commercial layer hens that go out of egg production, but still consume a laying ration with high calcium. 2

3 This is case in which broiler breeders had mineralization and focal lymphocytic nephritis. Mineral is an example of a thing or feature that has diagnostic significance. In this case, mineral deposition indicates chronic damage to renal tubular epithelium and could be due to chronic nephritis due to water deprivation, chronic nephritis due to disease such as infectious bronchitis, or feeding a high calcium diet to hens that were out of production and not able to use the calcium in egg shell formation. 3

4 Image A is a low power view showing multiple focal mineral (calcium salts) deposits in tubules. B shows these deposits at higher magnification. C shows a damaged tubule (on the left) with mineral and a giant cell. Interstitial tissue is expanded by lymphocytes and fibroblasts as shown in D. The cause for these lesions is not known, but infectious bronchitis is a rule out. 4

5 This image shows a tubule with mineral deposition. 5

6 The next slide shows deposition of urates. Urates are the end product of nitrogen metabolism in birds. Urates dissolve as tissue is processed, but leave a characteristic footprint of bluish radiating or feathery pattern. 6

7 Urates are the end product of nitrogen metabolism in birds. Kidney disease often leads to failure to eliminate urates resulting in urate accumulation in tissues and on the visceral surfaces of organs like liver and heart. Urate deposition on, and sometimes within, visceral organs is termed visceral gout or visceral urate accumulation. This case example comes from birds with renal disease, nephrosis in this case, associated with visceral urate deposition. 7

8 A is a low power view of a kidney with severe lesions, but urate deposits are in the center of this image. Post-mortem autolysis was extensive in this kidney. B is a higher magnification of A showing urates. C is a higher magnification of B. Note the feathery appearance that is characteristic of urates. D shows a focal urate deposit in a lung. 8

9 Hemosiderin appears as a brown granular pigment in H&E stained material. Prussian Blue is a special stain for iron that shows hemosiderin as blue, granular material. Hemosiderin can accumulate when there is excessive destruction of erythrocytes or if iron is present in excess amounts (failure of iron metabolism). Large amounts of hemosiderin are common in the livers of aquatic birds. 9

10 Images A-C are progressively higher magnifications of liver showing a granular brown pigment (hemosiderin) in the cytoplasm of hepatocytes. D is a Prussian Blue stained section showing the blue staining granules indicative of the presence of iron. 10

11 Melanin is a black pigment and the product of melanocytes. Melanin is present normally in the tissues of many avian species. 11

12 Images A-D show the presence of a black pigment melanin in the interstitial tissues of a testis from a patridge. This is a normal finding. 12

13 The next slide shows hemoglobin in the lumen of renal tubules. Hemoglobin has an orange hue. Its presence indicates excessive destruction of erythrocytes. 13

14 Images A-D are progressively higher magnifications of kidney showing accumulation of an orange-hued protein in the lumen of many tubules. Granules of hemoglobin are in the cytoplasm of some tubular epithelial cells (D). 14

15 Dust frequently is trapped in pulmonary macrophages and appears as a brown or black granular pigment. 15

16 Image A shows the accumulation of brown granular pigment in macrophages in the wall of a parabronchus. B is a higher magnification. 16

17 Plant material may be trapped in the lung. The next slide shows some examples. 17

18 Images A-C are progressively higher magnifications showing plant material within a large granuloma in the wall of a parabronchus. D is another lung with similar plant material in the wall of a parabronchus. 18

19 Amyloid is an abnormal protein that accumulates in tissues in some chronic diseases and may accumulate due to excessive production or failure to remove by enzymatic digestion. Amyloid occurs at a relative high incidence in the livers of some aquatic birds. 19

20 Image A show deposition of amyloid in the spleen. Note the homogenous eosinophilic appearance and absence of any body response. B is a Congo Red stain showing the orange color. Under polarized light, this stain will reveal amyloid as a having green birefringence. Image C shows deposition of amyloid expanding sinusoids of the liver. D is a higher magnification of C. 20