Color Doppler ultrasound diagnosis of intrarenal vein thrombosis: A rare case report and literature review

RATIONALE: We present a case of intrarenal vein thrombosis (IRVT) diagnosed by ultrasound (US). To the best of our knowledge, this is the first reported case in the imaging literature. PATIENT CONCERNS: A 15-year-old boy with a 4-year history of thrombocytopenic purpura presented to the emergency room with a 2-day history of sudden-onset severe left flank pain associated with gross hematuria. DIAGNOSES: Hypercholesterolemia, proteinuria, and elevated plasma creatinine level were present. The US examination showed obscurely structured, sparsely distributed arterial and venous flow signals, and an increased resistance index (RI) in a localized area. The diagnosis was acute renal failure and nephrotic syndrome accompanied by left IRVT. INTERVENTIONS: The patient was treated with anticoagulation therapy for 1 month. OUTCOMES: Clinical symptoms were relieved. The US re-examination revealed that the arterial flow spectra had returned to normal. Also, more venous flow signals were observed in the involved area, suggesting thrombolysis. LESSONS: This previously unreported case should alert sonographers to include IRVT in the differential diagnosis of flank pain associated with hematuria. In such cases, both kidneys and different areas of the same kidney should be scanned and compared. Some features, including an obscure structure and an increased RI for the involved area indicate possible IRVT.