Presentation
The probable causes of a pelvic mass found on physical examination or through radiologic studies are vastly different in prepubertal children than they are in adolescents or postmenopausal women (Table 14.4). A pelvic mass may be gynecologic in origin, or it may arise from the urinary tract or bowel. The gynecologic causes of a pelvic mass may be uterine, adnexal, or more specifically ovarian. Because of the small pelvic capacity of a prepubertal child, a pelvic mass very quickly becomes abdominal in location as it enlarges and may be palpable on examination. Ovarian masses in this age group may be asymptomatic, associated with chronic pressure-related bowel or bladder symptoms, or may present with acute pain caused by rupture or torsion. Abdominal or pelvic pain is one of the most frequent initial symptoms. The diagnosis of ovarian masses in prepubertal girls is difficult because the condition is rare in this age group and, consequently, there is a low index of suspicion. Many symptoms are nonspecific, and acute symptoms are more likely to be attributed to more common entities such as appendicitis. Abdominal palpation and bimanual rectoabdominal examination are important in any child who has nonspecific abdominal or pelvic symptoms. An ovarian mass that is abdominal in location can be confused with other abdominal masses occurring in children, such as Wilms’ tumor or neuroblastoma. Acute pain is often associated with torsion. The ovarian ligament becomes elongated as a result of the abdominal location of these tumors, thus creating a predisposition to torsion.
Diagnosis
Ultrasonography has become a valuable tool for diagnosing ovarian masses. The characteristics of a pelvic mass can be determined. Whereas both unilocular and multilocular cysts frequently resolve with observation, the finding of a solid component mandates surgical assessment because of the high risk of a germ cell tumor (22). Additional imaging studies, such as CT scanning, MRI, or Doppler flow studies, may be helpful in establishing the diagnosis (23).
Differential Diagnosis
Fewer than 2% of ovarian malignancies occur in children and adolescents (24). Ovarian tumors account for approximately 1% of all malignant tumors in these age groups. Germ cell tumors make up one half to two thirds of ovarian neoplasms in individuals younger than 20 years of age. A review of studies conducted from 1940 until 1975 concluded that 35% of all ovarian neoplasms occurring during childhood and adolescence were malignant (25). In girls younger than 9 years of age, approximately 80% of the ovarian neoplasms were found to be malignant (26,27). Germ cell tumors account for approximately 60% of ovarian neoplasms in children and adolescents compared with 20% of these tumors in adults (25). Epithelial neoplasms are rare in the prepubertal age group; thus, data usually are reported from referral centers. However, some reports include only neoplastic masses, whereas others include nonneoplastic masses; some series combine data from prepubertal and adolescent girls. However, one community survey of ovarian masses revealed that the frequency of malignancy was much lower than previously reported; of all ovarian masses confirmed surgically in childhood and adolescence, only 6% of patients with ovarian enlargement had malignant neoplasms, and only 10% of neoplasms were malignant (28). Surgicaldecision making clearly influences the statistics on incidence; the surgical excision of functional masses that would resolve in time inflates the percentage of benign masses. In one series, nonneoplastic masses in young women and girls younger than 20 years of age constituted two thirds of the total (29). Even in girls younger than 10 years of age, 60% of the masses were nonneoplastic, and two thirds of the neoplastic masses were benign. Functional, follicular cysts can occur in fetuses, newborns, and prepubertal children (30). Rarely, they may be associated with sexual precocity.
Management
A plan for the management of pelvic masses in prepubertal age girls is shown in Figure 14.8. Unilocular cysts are virtually always benign, even in this age group, and will regress in 3 to 6 months; thus, they do not require surgical management with oophorectomy or oophorocystectomy. Close observation is recommended, although there is a risk of ovarian torsion that must be discussed with the child’s parents (31). Recurrence rates after cyst aspiration (either ultrasonographically guided or with laparoscopy) may be as high as 50%. Attention should be directed to long-term effects on endocrine function as well as future fertility; preservation of ovarian tissue is a priority for patients with benign tumors. Premature surgical therapy for a functional ovarian mass can result in ovarian and tubal adhesions that can adversely affect future fertility. Solid masses, those larger than approximately 8 cm, and enlarging masses require surgical intervention.