To explore the clinical characteristics and diagnosis and treatment strategies of papillary urothelial neoplasms of low malignant potential(PUNLMP).

One pregnant woman with PUNLMP delivered on 4 August 2022 was selected into this study. A retrospective study method was used to collect the clinical case data of this patient, and summarize the clinical manifestations, diagnosis and treatment process.With " pregnancy with bladder tumor" " pregnancy with papillary urothelial neoplasms with low malignant potential" " bladder tumor" " papillary urothelial neoplasms of low malignant potential" and " pregnancy", relevant documents were searched in CNKI, Wanfang service platform and PubMed database and Web of Science (WOS) databases, and the search time was set as the database establishment from January 2004 to January 2023.The procedure followed in this study met requirements of the Helsinki Declaration of the World Medical Association revised in 2013, and signed clinical study informed consent with all subjects.

①Clinical characteristics of this patient were as follows. This patient was a 30-year-old primipara woman who developed " gross hematuria" at 25 gestational weeks and came to the hospital. Physical examination: no blood in the vagina and perianus; obstetric ultrasound: no abnormality; urological ultrasound results: the posterior wall of the bladder found 3.1 cm×2.5 cm×1.3 cm slightly strong echo; after one day, the urine blood stopped. Occasional urinary frequency and urgency, urology observation and follow-up. Macroscopic hematuria appeared again at 35 gestational weeks. Urinary tract ultrasound: in the posterior wall of the bladder, a slightly strong echo of 2.1 cm×1.7 cm×2.0 cm appeared, with a clear boundary, no exact blood flow signal, and no obvious position change. She went to the Department of Urology of West China Hospital again. The doctor considering that the bladder was a solid mass, the possibility of malignancy was not ruled out, and cystoscopy was recommended. After full doctor-patient communication, the patient chose to wait for delivery before handling the bladder space. The patient delivered a live male baby after 38^{+ 6} weeks of gestation. Routine results of urinary catheterization during delivery: occult blood (2+ ), urinary protein (-), urinary bacteria were 19 048 cells/μL, no purulent cells and pathological tubes.The puerperum recovered well, and no gross hematuria appeared postpartum.Transurethral bladder tumor resection of TURBT (88 days postpartum), postoperative pathological results: papillary tumor, supported the diagnosis of papillary urothelial neoplasms with low malignant potential.The patient recovered well from the puerperium, no postpartum gross hematuria, no urinary tract irritation symptoms, no low back pain and other discomfort.②Results of literature review were as follows.According to the literature search strategy, no literature on pregnancy with PUNLMP was retrieved, and 9 articles were found on 12 cases of pregnancy with bladder tumor, 11 cases received TRUBT during pregnancy and 1 case without TRUBT during pregnancy; all patients were not PUNLMP; only 3 patients received postoperative chemotherapy after definite diagnosis, and 1 case received mitomycin chemotherapy during pregnancy.

Pregnancy combined with PUNLMP is relatively rare clinically, and the mechanism of its occurrence is not clear. The choice of diagnosis should avoid the examination that may cause fetal malformation, and attention should be paid to the choice of treatment timing and regimen.