Synchronous bilateral benign ovarian neoplasms

A 45-year-old female patient (para 2 live 2) was referred to the Department of Gynaecology with non-specific complaints of pain in the abdomen on and off for 1 year, which was relieved by taking medication. Menstrual history was insignificant.

An ultrasonography (USG) report of the whole abdomen, which was done outside at a primary diagnostic centre, revealed a multi-loculated complex cystic lesion measuring 5.8 x 5.0 cm in the right adnexa, showing thin and thick internal septations, a few of which showed mild vascularity on colour Doppler, raising suspicion of a neoplastic aetiology of right ovarian origin. The right ovary was not seen separately or distinctly from the above-mentioned lesion.

However, USG suggested normal size and position of the left ovary. No obvious left adnexal mass was noted. The rest of the ultrasound findings revealed no other significant abnormalities.

Therefore, in view of USG findings, the patient was referred to the Radiology department for further evaluation by Magnetic Resonance Imaging (MRI) of the pelvis. CA-125 serum marker was also advised to rule out malignant pathology.

MRI findings revealed a multi-septated and multi-loculated complex cystic lesion measuring approximately 4.8 x 3.3 x 4.4 cm (AP x TR x CC) in the right adnexa. On T2-weighted images (T2WI), the lesion was predominantly hyperintense, with a few of the locules showing a T2-shading sign, suggesting clear and hemorrhagic fluid, respectively. The walls and septae of the lesion were thin, measuring less than 3 mm and appearing hypointense (Figure 1). On T1WI, one of the locules measuring 2.6 x 2.0 cm revealed a hyperintense signal (Figure 2), with no signal suppression on Fat-Sat images, which could indicate proteinaceous, mucin, or hemorrhagic contents (not fat) (Figures 3a, 3b). The right ovary was not visualised separately from the lesion. These imaging features of a right ovarian complex multilocular cystic lesion, showing thin septae, fluid and hemorrhagic signal intensity, and no obvious solid component or mural nodule, were consistent with the possibility of right ovarian mucinous cystadenoma.

In addition to the right adnexal lesion, a mixed solid-cystic lesion appearing hyperintense on T1 and T2-WI was also noted in the left adnexa, measuring 3.6 x 3.6 x 4.5 cm (AP x TR x CC) (Figures 4a, 4b). The lesion showed signal suppression on both T1 and T2 fat sat images, suggesting fat component (Figures 5a, 5b). Within the fat intensity lesion, multiple foci of hyper- and hypointense signals were noted on T2WI.

A fluid signal intensity area (T1 hypointense, T2 hyperintense) was noted along the supero-lateral aspect of the above-mentioned fat signal intensity lesion, measuring approximately 2.7 x 1.6 cm (AP x TR), likely representing the cystic component of the lesion or follicular cyst of the left ovary (refer to Figure 4). The left ovary was not visualised separately from the lesion, and these findings were consistent with a left ovarian dermoid cyst. This lesion was initially missed on USG.

The rest of the pelvic viscera (uterus and cervix) were unremarkable. Endometrial thickness was within normal limits, measuring 3 mm. Minimal free fluid was present in the pouch of Douglas. No significant pelvic lymphadenopathy was detected.

Based on the MRI findings, Serum CA-125 levels and histopathological evaluation were advised. Serum CA-125 levels were found within the normal range, i.e., 9.25 U/ml (Reference value: less than 35 U/ml).

In view of the complete family history of the patient and the explained risk of malignant transformation of either of the ovarian lesions, a panhysterectomy was performed (removal of the uterus, cervix, bilateral fallopian tubes, and ovaries), and a specimen was sent to the Department of Pathology. On gross examination, the left ovary revealed hair and greasy material, and the right ovary revealed sticky gelatinous material. Microscopic examination confirmed a right ovarian mucinous cystadenoma and a left ovarian dermoid.

The risk of developing an ovarian tumour in a female during her lifetime is 6-7%, and in women of reproductive age group, ovarian tumours account for two-thirds of cases [1]. In prepubertal and postmenopausal women, benign tumours are rare. Risk factors for developing ovarian tumours include early menarche and late menopause, infertility, tamoxifen therapy, hypothyroidism, cigarette smoking, and genetic causes.

According to the 2020 WHO classification, ovarian tumours were classified into surface epithelial neoplasms (69%), germ cell tumours (25%), sex cord stromal tumours (4%), and others on the basis of tumour cell origin. Surface epithelial neoplasm subtypes are serous, mucinous, endometroid, clear cell, seromucinous, and Brenners; these are categorised into benign, borderline, and malignant categories. Germ cell tumours include mature cystic teratomas, immature cystic teratomas, dysgerminomas, yolk sac tumours, embryonal carcinomas, choriocarcinomas, mixed germ cell tumours, monodermal teratomas, and gonandoblastomas. Sex cord stromal tumour subtypes are thecomas, fibromas, Sertoli-Leydig cell tumours, sclerosing stromal tumours, juvenile granulosa cell tumours, and adult granulosa cell tumours. Other types of ovarian tumours include mesenchymal tumours and metastases [2].

Ovarian tumours can be benign or malignant. The presence of solid components, thickened septa, papillary excrescences, or enhancing or vascular mural nodules raises suspicion of malignancy.

Our case describes bilateral benign ovarian neoplasms of different histopathological origins. The right ovarian mucinous cystadenoma is suggestive of an epithelial cell tumour, whereas the left ovarian dermoid (mature cystic teratoma) suggests germ cell origin. Mucinous cystadenoma comprises 15-20% of benign ovarian tumours [3]. Columnar epithelium lines these tumours, which is usually endocervical in type but occasionally may be intestinal in type, and secretes gelatinous, thick mucin filling the locules. Teratomas comprise 20% of benign ovarian tumours [4]. It is made up of well-differentiated descendants of the ectoderm, mesoderm, and endoderm germ cell layers that eventually become hair, muscle, teeth, or bone [5].

Most benign ovarian tumours are asymptomatic but may present as lower abdominal pain. The complications associated with them are torsion, haemorrhage, malignant transformation, and rupture. Pseudomyxoma peritonei is a condition caused by the rupture of a mucinous cyst, causing mucin to deposit in the peritoneum [6].

When two or more tumours develop in a patient at the same time, the term "synchronous tumour" is used. Female genital tract synchronous tumours are uncommon, comprising just 0.7% to 1.8% of all tumours in the female genital system [7]. Synchronous ovarian tumours are rare, and most of the reported cases are malignant. Mucinous tumours and mature teratomas are known to coexist, and approximately 2-11% of benign ovarian teratomas are associated with benign mucinous cystadenomas [8]. Early diagnosis and reporting of such cases is important for a better understanding of synchronous ovarian neoplasms, which may impact management strategies and prevent complications.

All patient data have been completely anonymised throughout the entire manuscript and related files.