Decoy cells detected in the urine of a patient with complex karyotype Myelodysplastic neoplasms who underwent umbilical cord blood transplantation: a case report.

Background: Currently, few literature reports document cases of decoy cells in the urine of umbilical cord blood transplant patients. The majority of the literature indicates that decoy cells are frequently identified in the urine of kidney transplant recipients.

Case presentation: This case report describes a patient with Myelodysplastic Neoplasms featuring a complex karyotype who underwent umbilical cord blood transplantation. Postoperative urinary cytology revealed decoy cells, and subsequent BK virus nucleic acid testing was positive. However, the routine use of antiviral drugs by the physicians led to insufficient attention to the decoy cells and BK virus, culminating in hemorrhagic cystitis.

Conclusions: Urine cytology is a simple, intuitive, rapid, and cost-effective analytical method. The presence of decoy cells in the urine can serve as an indicator for infection screening and provide a clue for clinical doctors: Detection of decoy cells in urine should prompt a more vigorous antiviral response to mitigate the risk of complications like hemorrhagic cystitis.