Malakoplakia of the Kidney Transplant

Introduction: Renal malacoplakia is a rare chronic granulomatous disease, often associated with immunosuppression and persistent Gram-negative infections, particularly Escherichia coli. Case Presentation: We present a case involving a 31-year-old woman with hypertension, gestational diabetes, and prior uterine curettage after labor induction for preeclampsia at 23 weeks. She developed urinary sepsis post-procedure. Imaging revealed bilateral nephromegaly, while laboratory tests showed acute kidney injury (KDIGO stage III), anemia, and thrombocytopenia. Blood and urine cultures grew Escherichia coli. Renal biopsy confirmed malacoplakia, demonstrating PAS-positive Michaelis–Gutmann bodies and Von Hansemann cells. The patient responded to prolonged antibiotic therapy and supportive care. Discussion and Conclusion: This case highlights the importance of considering renal malacoplakia in patients with atypical urinary tract infections and nephromegaly, particularly in obstetric settings. Histopathological confirmation is essential, and timely treatment with intracellularly active antibiotics can lead to favorable outcomes. Early diagnosis is critical to prevent irreversible renal damage.

脐尿管软斑病1例合并文献复习

Malakoplakia of the testis and epididymis: A case report and literature review

We report two cases of malakoplakia after kidney transplant, a rare granulomatous condition that occurs primarily in immunocompromised patients and his thought to occur due to incomplete clearance of phagocytized bacterial residue by macrophages. Both patients were at heightened immunological risk due to being highly sensitized or prior episodes of rejection, both experienced E. Coli infections in the first 4 months after transplant, and both presented with granulomatous masses that were biopsied and confirmed to be malakoplakia. Both were treated with suppressive antibiotics and required urinary drainage of the transplant kidney, resulting in improvements in the size of the mass on imaging. Given that both patients were at heightened immunological risk due to sensitization or episodes of rejection, we sought to investigate whether these are common risk factors for malakoplakia in the published literature. We summarized 59 published reports of malakoplakia in kidney transplant recipients. We found that malakoplakia cases predominantly occur in the first two years after transplant and that 47% of patients had either prior rejection or a prior transplant. We also found that many case reports of malakoplakia involve E. Coli infections and that improvement or resolution of malakoplakia was more common in case reports that did not involve surgical resection of the mass.

Xanthogranulomatous pyelonephritis (XPN) is a rare and unusual form of pyelonephritis that infrequently occurs in renal allografts. Clinical presentation ranges from asymptomatic to fever, pyuria, and graft dysfunction. We present a case of a young African American male who presented with a marked elevation in serum creatinine from a baseline of 1.8-1.9 to 9.86 mg/dL. Transplant kidney biopsy was consistent with the diagnosis of XPN, showing xanthoma cells, which are pathognomonic for this condition. Following antibiotic treatment, allograft function improved and return to dialysis was averted. Clinicians should consider XPN in transplant patients with deteriorating allograft function, as its presentation can mimic more common conditions. Graft salvage with appropriate antimicrobial therapy should be attempted before considering nephrectomy which risks reinitiation of dialysis.

BACKGROUNDMalakoplakia is a rare chronic granulomatous disease associated with gram-negative infection, predominantly by Escherichia coli. It is induced by defective phagolysosomal activity of the macrophages. Malakoplakia commonly affects the urinary bladder but has been shown to affect any solid organ, including the native and transplanted kidney. However, isolated malakoplakia of the kidney allograft is rare. Transplant recipients with compromised immune systems are more likely to develop malakoplakia.CASE SUMMARYWe report three cases of kidney allograft parenchymal malakoplakia in kidney transplant recipients on immunosuppression that were successfully managed with good outcomes. We described the clinical characteristics of all the kidney allograft malakoplakia cases documented in the literature. A total of 55 cases of malakoplakia were reported in recipients with a history of kidney transplant. A total of 27 recipients had malakoplakia involving the allograft, and others had malakoplakia in other organs. The common presentations included allograft dysfunction, pyelonephritis, and allograft or systemic mass. Most recipients had favorable outcomes with appropriate management that included prolonged antibiotic therapy and adjustment of immunosuppression. We reviewed the published literature on all the cases of malakoplakia in kidney transplant recipients so far and summarized the etiology, management, and outcomes.CONCLUSIONThis case series provides an overview of the etiology, presentation, pathogenesis, and management of malakoplakia in kidney transplant recipients.

Malakoplakia is a rare granulomatous disease characterized histologically by Michaelis-Gutmann bodies and sheets of macrophages with granular eosinophilic cytoplasm. While it most commonly affects the genitourinary tract, it can manifest in various locations, including cutaneous sites. This report details a rare example of scrotal malakoplakia in an 82-year-old man with a history of idiopathic pulmonary fibrosis, developing 7 months post-lung transplant, during ongoing chronic immunosuppressive therapy. Histopathological examination confirmed the diagnosis. This report highlights the importance of considering malakoplakia in the differential diagnosis of scrotal lesions, particularly in immunocompromised patients where the clinical presentation may be atypical.

To the Editor More than a century has passed since 1903, when Professor David von Hansemann described the presence of macrophages deposited in the form of a soft plaque and coined the term of Greek origin, malakoplakia (MLP). A year later, the morphologyof this cell with its own name was completed by the contribution of Michaelis and Gutmann, who pointed out the inclusions in its cytoplasm...