Extension of pancreatic pseudocyst into psoas muscle in a setting of acute pancreatitis.

Pancreatic pseudocysts are known to extend beyond the confines of the pancreatic bed due to the digestive nature of enzyme rich pancreatic fluid. Extension of a pseudocyst beyond the retroperitoneum, along the retrofascial plane within the psoas muscle is, however, unusual, with only a handful of cases described in the literature. We report a case of a 28-year-old man who presented with right lumbar pain and painful ipsilateral hip extension. Imaging findings revealed extension of the pseudocyst into psoas along with features of acute pancreatitis. The pseudocyst was drained percutaneously under image guidance, which led to resolution of symptoms.