Late-Onset Kidney Biopsy-Associated Retroperitoneal Hemorrhage in Lupus Nephritis: A Case Report of Pseudoaneurysm and Microaneurysm Formations.

Late-onset retroperitoneal hemorrhage from renal intraparenchymal pseudoaneurysm (RIP) following a kidney biopsy is an extremely rare complication but should not be ignored, especially in high-risk populations. Here, we introduce a 32-year-old Caucasian female who presented with sudden-onset left-sided flank pain. She had recently been diagnosed with systemic lupus erythematosus (SLE) and had undergone a computed tomography (CT)-guided core needle biopsy of the left kidney 9 days earlier.