Therapeutic Plasma Exchange in a Rare Case of Metastatic Pancreatic Carcinoma Presenting as Thrombotic Microangiopathy and Acute Kidney Injury

Thrombotic microangiopathy (TMA) represents a diverse group of conditions characterized by the presence of microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and ischemic end-organ injury. Thrombotic thrombocytopenic purpura (TTP) is an important cause of TMA requiring urgent identification and therapeutic plasma exchange (TPE). Cancer-related TMA is commonly misdiagnosed as TTP. In contrast to TTP, there is no clear evidence supporting the routine use of TPE in TMA associated with cancers. However, there are some case reports showing that TPE may also be useful in TMA not associated with TTP, such as cancer-related TMA. In fact, there are different postulated pathophysiology leading to this disease entity. Here, we present a rare case of TMA and acute kidney injury (AKI) secondary to metastatic pancreatic carcinoma who had a resolution of bleeding symptoms with complete hematological and renal recovery after four sessions of daily TPE. The patient finally died of cancer six months later. Our case shows that TPE could be valuable in cancer-related TMA in particular patients, especially those with clinical bleeding and thrombosis. The ability of TPE to remove abnormal components in the complement pathway and potential endothelial-damaging agents or autoantibodies and replace them with normal ones may explain its usefulness in some patients with cancer-related TMA.