Malignancy-Associated Renal Infarction: A Case of Prostate Cancer Presenting With Flank Pain and Hematuria.

Renal infarction is an uncommon but critical diagnosis that is frequently overlooked due to its nonspecific presentation and overlap with more common causes of abdominal or flank pain. Patients with malignancy, including metastatic prostate cancer, are at increased risk of thromboembolic events due to the intrinsic hypercoagulable state promoted by cancer, yet arterial events, such as renal infarction, remain underrecognized. We present the case of a 74-year-old male with metastatic castrate-sensitive prostate cancer who developed acute abdominal pain, nausea, and vomiting. Evaluation revealed elevated blood pressure, microscopic hematuria, and increased lactate dehydrogenase (LDH). CT scan of the abdomen and pelvis with contrast demonstrated wedge-shaped perfusion defects in the left kidney, consistent with renal infarction, allowing for the timely initiation of anticoagulation. This case underscores the importance of recognizing renal infarction as a potential complication of malignancy-associated thrombophilia. The classic triad of flank pain, hematuria, and elevated LDH should raise clinical suspicion, prompting early cross-sectional imaging to facilitate diagnosis and prevent irreversible renal injury.