Extensive thigh pyomyositis secondary to cystic fistulae due to anaerobic-bacterial infection in a kidney transplant recipient.

Background: Managing infectious complications after kidney transplantation (KT) remains a major challenge. Infections are the leading non-cardiovascular cause of death among kidney transplant recipients (KTr). The urinary tract is particularly vulnerable to infections in this group, leading to high levels of morbidity and mortality, as well as significant economic costs.

Case presentation: This case report presents the first documented instance of extensive thigh pyomyositis resulting from cystic fistulae in an 84-year-old KTr. The patient was referred to our hospital with acute onset fever, pain in the inner thighs and pyuria. A CT scan revealed bilateral pyomyositis of the thighs, characterized by multiple abscesses in the adductor muscles and hydroaerobic levels. Additionally, cystic fistulae complicated by pubic symphysis osteitis were identified.

Conclusion: In KTr, lower limb pyomyositis resulting from a urinary tract infection is an extremely rare and significantly worsens the overall prognosis for these patients.