Autoimmune hemolytic anemia associated with renal urothelial cancer: A case report and literature review

BACKGROUND: Autoimmune hemolytic anemia (AIHA) is hemolytic anemia characterized by autoantibodies directed against red blood cells. AIHA can be induced by hematological neoplasms such as malignant lymphoma, but is rarely observed in the urological field. We report a case of renal urothelial cancer inducing Coombs-positive warm AIHA and severe thrombocytopenia that was responsive to nephroureterectomy. CASE PRESENTATION: A 52-year-old man presented with a 1-month history of general weakness and dizziness. Hemoglobin level was 4.2 g/dL, and direct and indirect Coombs tests both yielded positive results. Abdominal computed tomography revealed huge left hydronephrosis due to a renal pelvic tumor measuring 4.0 x 4.0 x 3.0 cm, and renal regional lymph-node involvement was also observed and suspected as metastasis. Corticosteroid therapy was administered, and nephroureterectomy was performed. After surgical resection, the hemoglobin level gradually normalized, and direct and indirect Coombs tests yielded negative results. We thus diagnosed warm AIHA associated with renal urothelial cancer. CONCLUSION: To the best of our knowledge, this represents the first report of AIHA associated with renal urothelial cancer and severe thrombocytopenia responsive to nephroureterectomy. Renal urothelial cancer needs to be included in the differential diagnoses for warm AIHA, and nephroureterectomy represents a treatment option for AIHA.