Myeloid leukemia in a urine specimen: A case report and review of the literature

Urinary tract cytology has a long history of utilization for the diagnosis and follow-up of tumors involving the urothelial tract. As expected, the most common tumor encountered in exfoliative urine cytology is urothelial carcinoma. While the sensitivity of urinary tract cytology for the diagnosis of low-grade urothelial carcinomas is low, its sensitivity and accuracy for high grade urothelial carcinomas is much higher. However, nonurothelial malignancies, such as hematopoietic malignancies, can also be encountered in urine specimens. Leukemic cells in urine can be diagnosed readily by cytological examination in cases where more invasive procedures are difficult to perform. Additionally, cell block sections can be utilized to determine the immunocytochemical profile of the tumor cells to confirm the diagnosis. Herein we report a case of a 75-year-old man with a past medical history of acute myeloid leukemia (AML), who presented with congested heart failure and painless macroscopic hematuria. AML relapse was diagnosed. Cytological examination of the urine using a ThinPrep® smear, cytospin preparation, and immunohistochemical stains performed on the cell block sections were examined. Findings were consistent with leukemic cells of myeloid origin in the bladder washing specimen.