Multifocal lesions in a kidney allograft

Background Common complications following kidney transplant include infection, rejection, and malignancy. Multiple masses in a transplanted kidney raise suspicion for malignancy. Case Presentation A 20-year-old female with chronic kidney disease stage 3 T presented with graft tenderness, acute kidney injury, and heterogeneous masses in her transplanted kidney visualized via ultrasound. She was inadequately treated for chlamydia 1 month prior and retested positive upon admission. Initial workup revealed anemia, hyperglycemia, hyperuricemia, and elevated lactate dehydrogenase. Magnetic resonance imaging revealed complex masses of varying sizes in the transplanted kidney. Biopsy grew Streptococcus agalactiae , informing the diagnosis of multiple perinephric abscesses. Additional evaluations for infectious etiology were unremarkable. Her perinephric abscesses resolved with several months of antibiotics. Conclusions Even without a clear source, serious infections may develop in kidney transplant patients who otherwise have concern for malignancy. Chlamydial infections may lead to serious intra-abdominal infections in immunocompromised patients. The inadequately treated chlamydia likely led to polymicrobial ascension of the genitourinary tract that seeded the transplanted kidney. A high index of suspicion for infection is essential in immunosuppressed patients. Biopsy is crucial for a timely diagnosis.