Outgrowing skin involvement in malakoplakia after kidney transplantation: A case report

Introduction Malakoplakia is a rare pseudotumor that arises in the context of recurrent infections, particularly in immunocompromised states. We report a case of renal allograft parenchymal malakoplakia. Case report A 59-year-old woman successfully received a cadaveric renal transplant in June 2018. Two months after transplantation, she was treated for a urinary tract infection (UTI). In March 2019, she underwent allograft biopsy for increasing creatinine. The biopsy identified T cell mediated rejection and steroid pulse therapy was performed. In December 2019, she was hospitalized for right flank pain and pyuria, and her creatinine level was 1.9 mg/dL. Radiographic findings were suggestive of a hematoma or abscess in the perirenal area, and septated fluid collection was suspected. Biopsy results suggested malakoplakia, and von Kossa stain was positive for Michaelis- Gutmann bodies. Tissue culture demonstrated Escherichia coli, and this was treated with antibiotics. The dose of tacrolimus was reduced. The patient was discharged after 1 month of hospitalization and was maintained on oral antibiotics. Follow-up imaging revealed an increase in the extent of lesion into the adjacent abdominal wall. Assuming the case to be refractory, we performed surgical resection and abscess drainage. Although the renal parenchymal involvement persisted, the size showed a decreasing trend over 2 months of serial observation with ultrasonography. Conclusions Malakoplakia should be considered as a differential diagnosis for recurrent UTI with graft dysfunction. Malakoplakia can be successfully treated with reduction in immunosuppression and medical therapy using long-term antibiotic treatment in most cases. However, early surgical treatment must be considered for refractory cases.