Metastatic Lung Adenocarcinoma- Associated Thrombotic Microangiopathy in a Renal Transplant Recipient.

Thrombotic microangiopathy (TMA) after renal transplantation can be a diagnostic challenge. TMA can occur with calcineurin inhibitors, allograft rejection, infection, mutations in complement regulatory proteins and autoimmunity. A 52-year-old male renal transplant recipient presented with extensive deep vein thrombosis. He developed transfusion-dependent microangiopathic haemolytic anaemia with thrombocytopenia. He did not respond calcineurin inhibitor cessation, eculizumab or plasma exchange. ADAMTS13 and complement levels were normal. Infection and autoimmune screens were negative. A diagnosis of metastatic adenocarcinoma was made on bone marrow biopsy. This represents a rare case of malignancy-associated TMA in a renal transplant recipient. Early diagnosis can facilitate the prompt initiation of chemotherapy which is the only treatment option.