Clinical characteristics of all girls presenting with abdominal pain and a pelvic mass

212 patients were surgically evaluated for ovarian lesions with a symptom of abdominal pain. At the operation, the median age of the patients was 14.5 ± 3.6 years; 155 patients (73.1%, 155/212) had regular menstruation, 20 patients (9.4%, 20/212) had irregular menstruation, and 37 patients (17.5%, 37/212) were premenarchal.

Further, 126 (59.4%, 126/212) patients presented with an abrupt onset of abdominal pain. In addition to pain, the patients presented with other symptoms and objective findings. The incidence rate of vomiting, nausea, fever, diarrhea, frequent urination, and abnormal vaginal bleeding was 26.9%, 6.6%, 3.3%, 0.9%, 1.8%, respectively. One patient presented with the clinical characteristics of precocious puberty.

Pelvic abdominal ultrasound(US) was the priority imaging modality used in all the patients (100%, 212/212) to characterize the ovarian disease as predominantly cystic lesions or lesions with solid components. The US examination showed an adnexal mass in all patients: cystic ovarian masses in 188 (88.7%), lesions with solid components in 24 (11.3%). CT scan or MRI was performed for 39 patients (18.4%) to exclude suspected malignant pathologies. The serum levels of the tumor markers CA-125, CA-199, α-fetoprotein, and β-human chorionic gonadotropin were detected in 105 patients. The levels of tumor markers were abnormally elevated in 26 patients.

Surgical procedure for patients and pathology review

Among the 212 patients, 179 (84.5%, 179/212) underwent laparoscopic surgery with an average tumor size of 7.7 ± 3.4 cm, with no intraoperative or postoperative complications. The average tumor size of 33 patients (15.6%, 33/212) who underwent laparotomy was 12.9 ± 5.6 cm. The mean tumor size of patients undergoing laparotomy was significantly higher than that of patients undergoing laparoscopic surgery (P = 0.000). A total of 82.1% (174/212) of the participants underwent adnexal conservative surgery.

The pathologic examination demonstrated the adnexal mass with abdominal pain being mature cystic teratoma (33.5%, 71/212), simple cyst (18.9%, 40/212), mucinous or serous cystadenoma (11.3%, 24/212), corpus luteum cyst (9.0%, 19/212)( cysts became rupturing and hemorrhagic (bleed),while causing severe pelvic pain), para-ovarian cyst (8.0%, 17/212), endometriosis cyst (8.0%, 17/212), malignant germ cell tumor (3.8%,8/212), and sexual cord stromal cell tumor (3.3%, 7/212). Among complex lesions suspected as malignancy indicated by preoperative ultrasound in 14 patients, 6 were confirmed to be malignant germ cell tumors and 3 were sex cord stromal tumors.

Eight cases of malignant germ cell tumors were found, including four cases of endodermal sinus tumors, one case of mixed germ cell tumors (endodermal sinus tumor complicated with immature teratoma tumor), two cases of immature teratoma, and one case of dysgeminoma. The postoperative treatment of the eight cases was supplemented with three to six cycles of PEB/PEV chemotherapy. Further, seven cases of sex cord stromal cell tumors were found, including four cases of juvenile granulosa cell tumors, one case of malignant steroid cell tumors, and two cases of moderately differentiated Sertoli-Leydig cell tumors. Juvenile granulosa tumors and malignant steroid cell tumors were treated with adjuvant chemotherapy after the surgery.

Clinical characteristics comparing patients with torsion and those with an alternate diagnosis

Of the 212 patients, 78 (36.9%) cases had adnexal torsion, including adnexal mass, enlarged ovaries, and fallopian tubes; 16 (7.5%) cases had mass rupture; and 2 (0.9%) had ectopic pregnancy; one had pyosalpinx and one had appendicitis (Table 2). The patients were divided into two groups (mass rupture and ectopic pregnancy were excluded from the cohort): the torsion (TO, n = 78) group and the non-torsion (non-TO, n = 116) group. We compared the clinical presentation between the patients with torsion and those without torsion. The median age for girls with torsion was 14.0 y, compared with 14.9 y for girls with a mass but no torsion (P >0.05). The proportion of patients presented with acute onset pain, persistent or recurrent pain, and duration of pain less than 3 months was significantly higher in the TO group than in the non-TO group (P < 0.001). 69.2% of patients with torsion had fixed pain sites, compared with 42.2% in patients without torsion (P < 0.001). 23.1% of patients with torsion were pre-menarche, compared with 11.2% in girls without torsion (P = 0.044). The proportion of patients with age ≤ 11 years in the TO group was significantly higher than that in the non-TO group (P = 0.038). The symptom of nausea and vomiting was more common among girls with torsion (P < 0.0001). 88.5% of girls with torsion had an ovarian cyst/mass ≥ 5 cm, compared with 75.0% in girls without torsion (P = 0.038), but there was no significant difference in the size of the lesion when evaluated continuously (median with torsion 8.8 cm versus median without torsion 8.7 cm; P = 0.884) (Table 3).

Table 2 Final diagnosis of patient needing emergent attentionTable 3 Clinical characteristics in the two groups

Among the 78 patients with adnexal torsion, 72 patients had adnexal mass. The average diameter of the adnexal mass was 8.7 ± 3.1 cm; in 97.2% of patients, it was larger than 5 cm. The average torsion degree was 653.2 ± 419. Torsion occurred on the right side in 45(57.7%)patients and 33 (42.3%) cases on the left. The cysts were bilateral, and torsion occurred on right side in two patients. The most common pathologic types were mature teratoma and simple cyst, accounting for 29.4% and 25.6%, respectively, followed by para-ovarian cyst, serous/mucinous cystadenoma, and endometriosis cyst. One patient presented with torsion of enlarged ovarian, three patients with fallopian tube torsion, three cases with malignant germ cell tumor, and one patient with sex cord stromal tumor. 66.7% of girls underwent ovary-preserving surgery, compared with 92.2% in patients without torsion. Further, 23 patients (29.5%) underwent adnexectomy due to ovarian necrosis. Patients with necrosis had more torsion cycles than those without necrosis, the difference was not statistically significant (P = 0.021). The proportion of patients with necrosis whose pain duration was more than 72 h was higher than that of patients without necrosis (P = 0.700). Three patients underwent salpingectomy for tubal torsion in the girls with torsion (Table 4).

Table 4 Surgical method for patients with adnexal torsionFactors associated with adnexal mass torsion

Univariate and multivariate logistic regression was used to assess factors associated with adnexal mass torsion. The multivariate analyses confirmed that mass size greater than 5 cm, acute onset pain, persistent or recurrent pain were significantly associated with increased risk of torsion (Table 5). Notably, patients with mass size greater than 5 cm had 4.1 times the odds of developing torsion in the presence of a mass as compared with those with smaller masses (95% CI: 1.349–12.669). Patients presented with persistent or recurrent pain was associated with 24.2 times the odds of torsion (95%CI: 8.398–69.444), and acute onset pain was associated with 15.9 times the odds of torsion (95%CI: 6.164–41.075).

Table 5 univariate and multivariate analysis of risk factor for torsion