Single most likely diagnosis
- Splenic artery aneurysm: This condition can cause a thumping or pulsating sound in the upper left quadrant of the abdomen due to the turbulent blood flow through the aneurysm.
Other Likely diagnoses
- Abdominal aortic aneurysm (AAA) with retroperitoneal extension: Although AAA typically presents with a midline abdominal mass, a large aneurysm can extend into the upper left quadrant and cause a thumping sound.
- Renal artery stenosis: Stenosis of the renal artery can cause a bruit (thumping sound) in the upper left quadrant due to turbulent blood flow.
- Splenomegaly with portal hypertension: Enlargement of the spleen can cause a thumping sound due to increased blood flow through the splenic vessels.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Ruptured abdominal aortic aneurysm: A ruptured AAA is a life-threatening condition that requires immediate attention. Although it may not be the most likely cause of a thumping sound, it is crucial to rule out this diagnosis.
- Embolic event (e.g., splenic infarct): An embolic event can cause a thumping sound due to decreased blood flow to the affected organ.
Rare diagnoses
- Arteriovenous malformation (AVM) of the spleen: AVMs are rare vascular anomalies that can cause a thumping sound due to abnormal blood flow.
- Splenic vein thrombosis: Thrombosis of the splenic vein can cause a thumping sound due to increased blood flow through collateral vessels.