An 86-year-old man returned to the UK from Spain with symptoms suggestive of gastrointestinal bleeding. He was found to have an acute kidney injury and thrombocytopenia. Further investigations identified the presence of a microangiopathic hemolytic anemia, supporting the diagnosis of a thrombotic microangiopathy. Differentials included atypical hemolytic uremic syndrome and secondary thrombotic microangiopathy. Thrombotic thrombocytopenic purpura (TTP) and STEC (Shiga toxin-producing E. coli) hemolytic uremic syndrome were excluded by a normal ADAMTS-13 and negative E. coli serology and stool PCR. The patient was treated with blood and platelet transfusions. He received eculizumab and hemodialysis whilst a screen for secondary causes was undertaken. Thrombotic microangiopathy was shown to be secondary to recurrence of prostate cancer, which had been treated 16 years previously. He later recovered his renal function and receives ongoing hormonal treatment for his prostate cancer.