Polypoid Müllerianosis Mimicking Primary Gynecologic Malignancy

BACKGROUND: Müllerianosis is the ectopic presence of at least two distinct müllerian-derived tissues in extrauterine sites. This case report explores its origin, diagnosis, and treatment strategies. CASE: We report a biopsy-proven case of polypoid müllerianosis in the left distal ureter and parametrium, causing severe hydroureteronephrosis. Initial imaging raised concern for malignancy; however, histopathologic examination confirmed a benign lesion—polypoid müllerianosis. The patient underwent a modified radical hysterectomy with partial ureteral resection and reimplantation to relieve the obstruction and resect the affected segment en bloc with the primary gynecologic mass. CONCLUSION: This case highlights the importance of a multidisciplinary approach in diagnosing rare conditions such as polypoid müllerianosis. Collaborative efforts between gynecologists, urologists, and pathologists are essential for accurate diagnosis and optimal treatment planning.