To discuss the pathogenesis, clinical manifestations, pathological features, diagnosis methods and treatment strategies of malacoplakia.

Through the report of a case of diagnosis and treatment of multi-system malacoplakia of the kidney, liver and colon, the disease was discussed in combination with the existing literature. A 65-year-old female patient presented to the doctor with "right side waist and abdomen pain for 1 month". Preoperative imaging examination revealed: right kidney space-occupying lesions, considering the possibility of renal cancer and infection, invasion of liver flexure of the colon, and involvement of the right lobe of the liver.

The patient with malacoplakia underwent ultrasound-guided puncture biopsy, laparoscopic radical resection of the right kidney and partial liver resection and colon hepatectomy to remove the diseased tissue. Postoperative pathology showed: right kidney, liver and colonic soft spot disease. Cooperate anti-infective treatment, the patient got recovery and discharged smoothly. one month after operation, the patient had no back pain and fever, and the rash had subsided. All indicators rechecked were normal. The enhanced CT of the whole abdomen showed that the right kidney was absent after the operation, and the right adrenal gland was unclear after partial resection; the lower part of the right liver lobe was absent; a small amount of encapsulated fluid in the right posterior peritoneal cavity and thickened peritoneum.

Malacoplakia is very rare, and the incidence of multi-system malacoplakia is lower. It needs to be diagnosed in combination with clinical manifestations, imaging, and molecular pathology. The disease is related to host immune deficiency. For multiple system malacoplakia, surgery is still an effective treatment. Long-term antibiotic treatment is required after surgery, which can improve symptoms, but is prone to relapse.