Abdominal Magnetic Resonance Imaging (MRI) Findings Prompting the Diagnosis of Paroxysmal Nocturnal Hemoglobinuria: A Case Report.

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic disorder with a nonspecific clinical presentation that often delays the diagnosis. We present the case of a 32-year-old female patient who presented with diffuse abdominal pain, fatigue, and anemia. An abdominal ultrasound was performed, revealing hepatosplenomegaly, and a subsequent abdominal magnetic resonance imaging (MRI) identified diffuse, symmetrical renal cortical hypointense signal, consistent with chronic iron deposits due to intravascular hemolysis, together with absent hepatic venous flow and lack of venous enhancement, indicating chronic hepatic venous outflow obstruction consistent with Budd-Chiari syndrome. The combination of renal hemosiderosis with venous thrombosis at an unusual site prompted a hematological evaluation, which confirmed the diagnosis. This case reinforces a well-recognized imaging pattern that helps radiologists suspect this entity, thereby enabling timely diagnosis and treatment.