27 July 2023
: Case report 
The Role of Aquaporin 1 in Water Retention Mechanism of Arachnoid Cysts: Insights from 3 Case Reports
Unknown etiology, Challenging differential diagnosis
Yasutaka Kurokawa12ABCDEF*, Masanori Ishiguro3BC, Takayuki Kurokawa
4EF
DOI: 10.12659/AJCR.939834
Am J Case Rep 2023; 24:e939834
Table 1. Results of aquaporin staining.
| Aquaporin | Case 1 | Case 2 | Case 3 | Control (kidney) |
|---|---|---|---|---|
| AQP1 | + | + | + | *1 in glomeruli, proximal tubules |
| AQP2 | – | – | – | *1 only in brush border |
| AQP3 | – | – | – | *1 only in proximal tubules |
| AQP4 | – | – | – | + only in loops of Henle |
| AQP5 | + in nuclei | *1 in nuclei | + in nuclei | + in nuclei |
| AQP9 | – | – | – | – |
| ‘–‘ – negative; + – positive; *1 – widely positive. | ||||