PMC9577014_01
(A,B) The ultrasonography report of the dysplastic kidneys. The results showed cystic formation and mineralization with ill-defined corticomedullary distinction and irregular margin. The size of the left kidney (3.98 x 2.01 cm) (A) was smaller than the right kidney (4.81 x 2.27 cm) (B). (C,D) The macroscopic findings of the dysplastic kidneys were characterized by small irregular surfaces (C). Multiple cysts showed in the renal parenchyma of both the left and right kidneys (D). L = Left kidney, R = Right kidney.
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F1
Besides, the abdominal ultrasonography demonstrated bilateral nephropathy with cystic formation and mineralization on both sides with ill-defined corticomedullary distinction and irregular margin (Figure 1). The size of the left and right kidneys were 3.98 x 2.01 cm (Figure 1A) and 4.81 x 2.27 cm (Figure 1B), respectively. Both kidneys were smaller and irregularly shaped; the left kidney was shrunken compared to the right kidney which was firm (Figure 1C). The cut surface also revealed that cysts with a maximum size of 4 mm were found in the renal cortex and medulla (Figure 1D).
The immature (fetal) glomeruli (arrow), immature (fetal) tubules (asterisk), and proliferative arterioles (arrow head) were demonstrated in the corticomedullary area of the kidney (A). Methanephric ducts were characterized by hyperchromatic, pseudostratified, and columnar epithelium, surrounded by interstitial fibrosis and loose mesenchyme (B). Atypical tubular epithelium (arrow) was characterized by the dilated adenomatoid cuboidal epithelium of collecting ducts (C). Persistent mesenchyme (asterisks) had been significantly observed in both cortex and medulla (D). The cortical tubules were infrequently found which were characterized by the hyperplastic (one to three layers into the inner lumina) of the epithelial cells (arrow) (E). Mild to moderate lymphoplasmacytic interstitial nephritis was displayed (F) (H&E stain, scale bar = 50 mum).
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F2
The fetal glomeruli and tubules were typically observed with proliferative arterioles and interstitial fibrosis (Figure 2A). In the inner renal cortex, metanephric ducts and atypical tubular epithelium were detected regularly (Figures 2B,C). The persistent mesenchyme was significantly discovered in both the renal cortex and medulla (Figure 2D). Moreover, irregular hyperplasia of the cortical tubule epithelium was observed infrequently (Figure 2E). Besides, mild to moderate lymphoplasmacytic interstitial nephritis was displayed (Figure 2F).
(A,B) The interstitial fibrosis surrounding the segmental nephrons and associated with the dilation of tubules (arrows), dilatation of Bowman's space (asterisks), and atrophic glomerulus (arrowheads) was frequently noted in the corticomedullary junction of the kidney (A) (H&E stain). Masson's trichrome stain was performed to confirm the presence of fibrotic tissue, which presented a positive blue color (B). (C,D) Localized mineralization (arrows) in the lumen of the renal tubules was observed (H&E staining) (C), which is confirmed by Von Kossa stain (D) (Mayer's Hematoxylin counterstained, scale bar = 50 mum).
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F3
For the special stains, interstitial fibrosis (Figure 3A) was confirmed by Masson's trichrome stain (Figure 3B). The mineralization of renal tubules (Figure 3C) was confirmed by the Von Kossa stain (Figure 3D).
(A,B) The positive labeling of BCL-2 in the negative control dog (A) and the affected dog (B). Strong labeling of BCL-2 showed the localization of immature (fetal) tubules (arrows) (B). (C,D) The CD31 (PECAM-1) positive labeling in the blood vessels of the negative control dog (C) and the affected dog (D). The blood vessels (arrow) were labeled within glomeruli and surrounding areas (Immunohistochemistry, Mayer's Hematoxylin counterstained, scale bar = 50 mum). (E) The number of blood vessels per HPF (40X) in the negative control dog (Control) and the affected dog (RD). Blood vessel count was performed via the positive label of CD31 (PECAM-1) in the kidney of dogs. Data were displayed as mean +- SD. *** The significant difference among dogs (p < 0.01) was evaluated by the t-test, using the SAS software version 9 (SAS Institute, Inc., USA).
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F4
The BCL-2 showed cytoplasmic labeling in the epithelial cells of immature (fetal) tubules (Figure 4B). In this study, the proliferative arterioles were shown in the area surrounding glomeruli and tubules (Figures 4C,D). The number of blood vessels was significantly different between the RD-affected dog and the negative control dog (p < 0.01; Figure 4E).