Young Man With Non-hypertensive Ascites of Unexpected Cause: When Ockham's Razor Is Not Sufficient.

Ascites is defined as the accumulation of fluid in the peritoneal cavity, following an imbalance between production and reabsorption; it is detectable from 50 mL on ultrasound. Three mechanisms have been classically implicated, according to Starling's forces: an increase in the hydrostatic pressure gradient (increased portal venous pressure), a reduction in the oncotic pressure gradient (loss of total proteins, especially albumin), and an increase in peritoneal capillary permeability. This latter mechanism, plus the difference between lymph production and excretion (which favors the accumulation of exudate), explains some of the most notable causes of non-hypertensive ascites (according to the serum albumin in ascites gradient (SAAG)), including peritoneal carcinomatosis and tuberculosis. We present the case of a young man, originally from a tuberculosis endemic area, in whom the study of ascitic fluid guided the workup and the definitive diagnosis, which was unexpected for his age. Finally, a practical approach to non-hypertensive ascites is provided.