Perinephric hematoma induced by factor Xa inhibitor in a patient with a vascular renal mass

Perinephric hematomas are known to present in the form of Lenk's triad with acute flank pain, flank mass and hypovolemic shock. Here, we describe a case of perinephric hematoma occurring secondary to the use of anticoagulant therapy in the setting of a renal mass. To the best of our knowledge, this is the first reported case of a perinephric hematoma occurring secondary to the use of Apixaban. The patient was an 80 year old male with a history of the presence of a left sided vascular renal mass discovered seven years ago admitted from a peripheral health center with pneumonia and a dropping hemoglobin along with acute kidney injury. Evaluation of his course revealed the use of a Factor Xa inhibitor, namely Apixaban, for new onset atrial fibrillation. The patient was stabilized with multiple units of packed red blood cell transfusions. An abdominal computed tomography abdomen demonstrated a perinephric hematoma contained in the Gerotas fascia. Due to deranged renal function, the patient was managed conservatively and made a full recovery. This case highlights the challenges associated with the diagnosis of perinephric bleeds. The use of anticoagulation therapy in the setting of a pre-existing vascular lesion remains a dilemma.