Childhood years

Childhood presentation of adnexal masses rarely occurs. In the neonatal period, functional ovarian cysts may be present secondary to stimulation by maternal hormones. Other possible abdominal masses are Wilms’ tumors or neuroblastomas. However, if an adnexal neoplasm does appear, it tends to be a germ cell tumor such as dysgerminomas or teratomas.

Adolescent years

During adolescence, the most common adnexal pathology is a functional cyst, which can vary in size from 3 to 10 cm. As the name suggests, functional cysts arise from the physiologic follicle maturation process associated with ovulation. These cysts are either follicular or corpus luteum cysts and will eventually disappear with subsequent menstrual cycles.

One of the most common presentations of an adnexal mass in this age group is adnexal torsion. Under torsion, the blood supply to the ovary decreases or subsides, placing the ovary at risk of death. The risk of ovarian death and altered fertility makes torsion a surgical emergency in this age group. Benign teratomas in this age group will frequently present under torsion.

Malignant ovarian tumors, in this age group, tend to be germ cell cancers. About 70% of ovarian tumors found during childhood and adolescence originate from germ cells [1].

Reproductive years

A variety of pelvic masses arise during the reproductive years. Pedunculated myomas of the uterus and, rarely, the cervix may appear to arise from the adnexa. Abnormal placentation of an embryo, an ectopic pregnancy, will also appear as an adnexal mass on transvaginal ultrasound. Remnants of the mesonephric ducts may resemble cystic pelvic masses. Endometriomas are also described as adnexal masses. Polycystic ovary syndrome also causes abnormal ovarian morphology. Untreated or undertreated pelvic inflammatory disease may progress to formation of an intrapelvic abscess; when associated with the ovary it is known as a tubo-ovarian abscess.

Despite the varied possible diagnoses in this age group, about 13% of women during their reproductive years will have a malignant ovarian neoplasm [2]. Histologically, the majority of malignant ovarian neoplasms are epithelial. A substantial percentage of these neoplasms will fall into the category of low malignant potential (borderline) tumors. These types of tumors separate themselves from invasive ovarian carcinoma by their often indolent behavior. Subsequently, a diagnosis of a borderline tumor has an excellent prognosis. Other cell types include germ cell and sex cord stromal. Benign ovarian neoplasms include serous and mucinous cystadenomas, which can vary in size from 5 cm to over 20 cm. Mucinous cystadenomas are known for their large size on presentation. Still, the most common adnexal masses between the ages of 20 and 40 are functional ovarian cysts, and the most common neoplasms are benign teratomas.

Perimenopausal/menopausal years

As with all neoplastic processes, advancing age places a woman at higher risk for developing both benign and malignant ovarian carcinomas. About 80–90% of all ovarian cancers, including borderline tumors, will occur after the age of 40 [1]. The majority of these diagnoses are epithelial ovarian cancers with a serous histologic type. Twenty percent of epithelial ovarian cancers are mucinous, endometrioid, clear cell, Brenner or undifferentiated histology types [1]. Simple benign cysts still occur in 18% of postmenopausal women [3]. Germ cell tumors are extremely rare in women over the age of 40.

Reproductive and genetic factors influence the incidence of ovarian cancer. In an epidemiologic study by Adami et al. in Sweden [17], it was noted that increasing parity resulted in a subsequent decrease in relative risk for invasive ovarian cancer. They also noted a decrease in odds ratio between the age of uniparous women and ovarian cancer: women who gave birth at age 35 + had a lower odds ratio than those who gave birth at 20. However, the protective effects of parity did not alter the incidence of borderline tumor. Oral contraceptive pill (OCP) usage has also been proven to decrease the relative risk of ovarian cancer by about 40%, although the maximal protective effects occur after 5 years of usage [4].

While the majority of ovarian cancer cases arise from sporadic mutations, about 10% have an autosomal dominant inheritance related to three genetic mutations [5]. The most commonly known are the BRCA 1 and 2 mutations on chromosome 13 and 17; the third mutation is a mutation in the DNA mismatch repair genes associated with hereditary nonpolyposis colon cancer. BRCA mutations cause about 90% of all inherited ovarian cancer. The increased risk associated with the BRCA gene mutations ranges from 30% with BRCA 2 to 60% with BRCA 1. Despite the increased risk, evidence suggests an improved survival rate for these patients. Patients with these associated mutations may undergo prophylactic bilateral salpingo-oophorectomies in order to prevent occurrence of disease.

Our current understanding of ovarian epithelial carcinoma roots itself in the hypothesis that unhindered ovulation causing rupture of the ovarian epithelium and subsequent activation of molecular repair mechanisms gives rise to mutations leading to ovarian cancer. Although chemoproventive data from OCPs support this theory, further analysis reveals that OCPs decrease ovulation only by 15% but the risk for ovarian cancer falls by 50% with OCP usage. Epidemiologic studies on the protective effects of parity also lend credence to the ovulatory hypothesis of ovarian cancer.

Recent investigations demonstrate that 90% of epithelial ovarian carcinomas arise from a monoclonal mutation suggesting that a premalignant lesion occurs within the ovary or fallopian tube after accumulation of multiple mutations [4]. The difficulty lies in finding a premalignant lesion within either organ. A commentary by Dubeau questions the old adage that epithelial carcinoma of the ovarian arises from unhindered ovulation by pointing out two inconsistencies: (1) the mullerian-like histology of epithelial ovarian carcinoma and (2) rare occurrence of preneoplastic changes of the ovarian epithelium. He proposes that epithelial ovarian carcinomas originate from the secondary mullerian system that contributes to the formation of paraovarian/paratubal cyst, rete ovarii, and endometriosis [18].