Drug-Induced Thrombotic Microangiopathy Arising During the Treatment of Anal Carcinoma After the Use of Mitomycin C

Anal cancer is a rare disease where malignant cells originate in the tissues of the anal canal. This form of cancer is classically treated with a combination of radiation therapy and a chemotherapy regimen that includes mitomycin C. This case illustrates an unusual presentation of thrombotic microangiopathy associated with mitomycin C. A 57-year-old woman with a history of anal carcinoma treated with capecitabine/mitomycin C and radiation was sent to the emergency department by her oncologist for an incidental finding of worsening kidney function noted on a complete metabolic panel done prior to getting radiographic imaging. The patient was admitted to the hospital for suspected acute kidney injury from suspected ureteral obstruction and stent occlusion; however, despite reversal of the stents, renal function did not improve. Renal biopsy confirmed thrombotic microangiopathy and diagnosis of drug-induced thrombotic microangiopathy. This case discusses a side effect of thrombotic microangiopathy from mitomycin C and successful treatment with eculizumab.