Giant hydronephrosis presenting as an acute abdomen.

Background: Giant hydronephrosis is a relatively rare condition caused by obstruction of the renal collecting system that can present with a great number of different types of abdominal signs and symptoms.

Case Report: A 40-year-old man without past medical history presented to the Emergency Department with diffuse abdominal pain, nausea, and vomiting. On examination, he was found to have an acute abdomen. Computed tomography scan revealed left giant hydronephrosis secondary to an obstructing renal calculus. The patient had a left percutaneous nephrostomy tube placed, which drained over 7 L of fluid from the dilatated collecting system.

Conclusion: Giant hydronephrosis is a rare potential cause of abdominal pain, particularly in the context of a patient with known nephrolithiasis, structural urologic abnormalities, or malignancy.