Results
Overall, 350 children were identified from 18 centers. Table 1 describes the patient and tumor characteristics. The median age at tumor diagnosis was 11 years (range, 0-17). Data on OMT affecting another family member, most frequently at the first-degree level (80%), was retrieved in 10 cases (3%). None involved three consecutive generations. Genetic investigations were conducted in seven cases, but no anomalies were identified. Past medical history revealed a known germinal genetic anomaly in two children without other OMTs in the family: STIM1pathogenic variant in exon 7 (one case) and familial SNX10pathogenic variant (one case).
The most frequent revealing symptom was abdominal pain in 61% of cases, 40% being related to adnexal torsion. Large palpable masses (27%), urinary disorders (6%) and transit disorders (22%) were the other symptoms, and these were explained by the tumor volume and local compression. Also, menstrual cycle disorders were noted (4%). Data on pubertal status were available for 51% of females, and 59% of them had achieved puberty with onset menarche. An early puberty’s context was observed in 12 cases (3%). These patients presented a median age of nine years at OMT diagnosis. For seven of them, the early puberty was considered unrelated to the OMT. OMT was incidentally diagnosed in 25% of cases. Data on serum tumor markers (AFP and HCG) were available in 330 cases, being negative in 325 cases (98%). A low increase in AFP was noted in five cases (1.5%). Eighteen patients (5%) presented synchronous bilateral OMT at diagnosis.
Surgical procedures were carried out with a median delay of 10.5 days (range, 0-1504) after diagnosis, 72% of them being planned and 28% performed as an emergency. Adnexal torsions (n= 87) represented 76% of emergency surgeries and were managed by laparoscopic detorsion associated with tumor resection in one- or two-step procedures. TO was performed in 57% of adnexal torsion cases. Tables 1 and 2 describe the initial surgical management characteristics of the whole cohort. Laparotomy was performed in 83% of cases, was performed as a single procedure in 53% of cases, was associated with initial exploratory laparoscopy in 32% of cases. Fifteen percent of the cohort underwent exclusive laparoscopy. OSS was performed in 56% of unilateral OMTs and in all bilateral OMTs. Considering the whole cohort, OSS was performed in 59% of cases (n=208), and TO was performed in the other cases (n=142). TO was performed by laparotomy associated or not to laparoscopy in 87% of cases and by laparoscopy in 13% (Table 2).
Preoperative rupture was suspected and confirmed during surgery in eight cases. Perioperative tumor rupture occurred in 23 cases (7%). If perioperative rupture was more frequent when laparoscopy was performed (11.3%), this was not significant (p=0.09) (Table 2).
All tumors underwent macroscopic complete resection independently of the surgical approach. No peritoneal tumor spreading was observed on peritoneal cytologic examination of the collected fluids, which was performed systematically in all cases. Pathologic examination of the specimen revealed minor associated immature malignant components in seven cases, all of which exhibited moderate serum AFP elevation.