Prostatic malakoplakia: a rare case report and literature review

Malakoplakia is an extremely rare chronic inflammatory disorder, most commonly affecting the genitourinary tract. Prostatic malakoplakia is particularly uncommon. Its elevated serum prostate-specific antigen (PSA) levels, magnetic resonance imaging (MRI) findings, and clinical symptoms closely mimic those of prostate cancer, leading to a high risk of misdiagnosis. Here we report a 64-year-old male patient presenting with gross hematuria, frequency, and urgency. Laboratory tests revealed elevated inflammatory markers and a serum PSA of 8.72 ng/mL. Multiparametric MRI (mpMRI) showed a Prostate Imaging Reporting and Data System (PI-RADS) score of 4, raising high suspicion of prostate cancer. Transrectal ultrasound-guided prostate biopsy was performed. Histopathology showed diffuse infiltration by histiocytes containing characteristic Michaelis-Gutmann (MG) bodies with typical morphological features on hematoxylin and eosin (H&E) staining. Immunohistochemistry confirmed prostatic malakoplakia and ruled out malignancy. After treatment with piperacillin sodium, the patient’s symptoms resolved completely. Follow-up at one month showed normalization of inflammatory markers and PSA. This article also narrative literature review 90 cases reported in the past 30 years, summarizing the clinical presentation, imaging features, pathological characteristics, diagnosis, differential diagnosis, and treatment strategies for prostatic malakoplakia. In patients with elevated PSA and mpMRI findings suspicious for prostate cancer, if the lesion shows diffuse symmetric distribution, an intact capsule, and delayed periprostatic enhancement, prostatic malakoplakia should be included in the differential diagnosis. Definitive diagnosis depends on pathological identification of MG bodies. Antibiotic therapy appears to be effective in most reported cases, and the prognosis is generally favorable.