retroperitoneum

n. retroperitoneal space, space located behind the abdominal cavity

The retroperitoneum (adj. retroperitoneal) is the anatomical space behind (retro) the abdominal cavity. It has no specific delineating anatomical structures. Organs are retroperitoneal if they only have peritoneum on their anterior side. Retroperitoneal cancer has one of the lowest survival rates of all cancers.
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Retroperitoneum /ret·ro·peri·to·ne·um/ retroperitoneal space. ret·ro·per·i·to·ne·um n. The retroperitoneal space. [more]Retroperitoneum - Community and Resources