Massive empyema can mimic tension pneumothorax clinically and can be distinguished only radiographically. This distinction is crucial since needle decompression for tension pneumothorax can cause iatrogenic pneumothorax in those with massive empyema.

A 56-year-old woman was found to have retroperitoneal hemorrhage secondary to isolated posterior inferior pancreaticoduodenal artery (PIPDA) dissection. She had chronic abdominal pain and celiac artery stenosis, suggesting that PIPDA dissection was associated with celiac artery compression syndrome (CACS). Clinicians may consider CACS as the cause of visceral dissection.