Objective  To investigate the clinical characteristics of hysteroscopic patients and to discuss some inconclusive questions in hysteroscopy.

  Methods  A total of 315 patients who underwent hysteroscopy in Peking Union Medical College Hospital from July to December, 2014 were included in this retrospective study. Clinical and pathological features of these patients were summarized. Clinically relevant inconclusive questions including PALM-COEIN classification, ultrasonic diagnosis of endometrial polyp, case characteristics of adenomyomatous polyp, intrauterine space-occupying lesion induced by adjuvant endocrine therapy for breast cancer, and uterine scar diverticulum were analyzed based on the data of these patients.

  Results  Among the 315 patients, 172 cases presented with abnormal uterine bleeding (AUB), and the other 143 were asymptomatic. Malignant lesions were more common in AUB patients compared with asymptomatic patients (15.7% vs. 2.1%, P=0.000). In the AUB patients, 128 were of reproductive age, in whom the most common condition was endometrial polyps (58 cases, 45.3%) according to PALM-COEIN classification system. All together 160 cases of endometrial polyps were identified. The positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of transvaginal ultrasound in diagnosing endometrial polyps were 80%, 75%, 71%, 81%, and 76%, respectively. Seventeen patients had adenomyomatous polyp, including 3 with atypical pathological features; 10 patients had history of surgically treated breast cancer, 9 of whom received adjuvant endocrine therapy, and all had benign results of endometrial pathological examination; 5 patients had scar diverticulum after cesarean section, all with specific hysteroscopic demonstrations.

  Conclusions  As a minimally invasive technique, hysteroscopy plays an important role in diagnosis and treatment of AUB and intrauterine space-occupying lesion. For most benign lesions, such as endometrial polyps, endometrial hyperplasia following postoperative endocrine therapy of breast cancer, and cesarean scare diverticulum, hysteroscopy allows therapeutic operation while confirming diagnosis. Investigation into hot topics in diagnosis and treatment with hysteroscopy could help to optimize clinical strategies.