RESUMO
<p><b>OBJECTIVE</b>To study the diagnosis and treatment of Müllerian duct cysts and their involvement with malignancy.</p><p><b>METHODS</b>A 44-year-old male patient with papillary cystadenocarcinoma involving a Müllerian duct cyst was presented. The presentation treatment, and pathological and radiological appearances were retrospectively analysed and discussed with literature review. The main manifestation was intermittent episode of hemospermia accompanying terminal hematuria and infertility for 15 years. Final diagnosis was determined by the findings of transrectal ultrasound scan, CT scan, MRI imaging, cystoscopic examination and biopsy.</p><p><b>RESULTS</b>Exploratory laparotomy was performed through a suprapubic retrovesical approach. The finding that a duct-like wedge of tumor tissue passed through the prostate near cyst neck to the posterior urethra without affecting the adjacent prostatic tissue during tylectomy confirmed that it arises from Müllerian duct system. Pathohistologic examination disclosed a papillary cystadenocarcinoma and it infiltrated the wall of the cyst. Both seminal vesicles and ejaculatory duct had no carcinoma invasion.</p><p><b>CONCLUSION</b>Müllerian duct cyst involving with malignancy is exceedingly rare, the diagnosis is based on the findings of transrectal ultrasound scan, CT scan, MRI imaging, cystoscopic examination. The final diagnosis depends on the pathohistologic examination. Lumpectomy is effective and have a good outcome.</p>