Ovarian Tumours

Ovarian tumours are a histologically diverse group of neoplasms arising from the ovary, classified by cell of origin into three categories:

• epithelial tumours, the commonest category overall, arising from the ovarian surface epithelium and including the majority of both benign and malignant ovarian neoplasms
• germ cell tumours, arising from the primordial germ cells, particularly relevant in children and young women
• sex cord-stromal tumours, arising from the supporting, hormone-producing tissue of the ovary, with a subset of subtypes that secrete distinctive hormones

Each category is further subdivided into benign, borderline, and malignant subtypes. This classification underpins both diagnostic evaluation and management.

Classification by cell of origin

• Epithelial tumours account for the substantial majority of ovarian neoplasms and the overwhelming majority of ovarian malignancy. Subtypes are serous, mucinous, endometrioid, and clear cell.
• Each epithelial subtype spans benign (cystadenoma), borderline and malignant (carcinoma) forms. Borderline tumours (low malignant potential) show atypical epithelial proliferation without frank stromal invasion and have a generally favourable prognosis distinct from invasive malignancy.
• High-grade serous carcinoma is the commonest and, given its typically advanced stage at presentation, most clinically significant malignant subtype.
• Germ cell tumours are particularly relevant in children, adolescents, and young women. The benign mature cystic teratoma (dermoid cyst) is the commonest germ cell tumour overall.
• Malignant germ cell tumours are less common and include dysgerminoma, yolk sac tumour, and immature teratoma. They generally show excellent chemosensitivity and a favourable prognosis with prompt treatment, in contrast to the less favourable prognosis of the commoner epithelial ovarian malignancies.
• Sex cord-stromal tumours arise from the ovarian stromal and supporting cell populations. Granulosa cell tumours can secrete oestrogen, sometimes presenting with endometrial hyperplasia or abnormal uterine bleeding or, in a prepubertal girl, precocious puberty.
• Sertoli-Leydig cell tumours can secrete androgens, presenting with virilisation.

• Presentation varies with tumour type, size, and any hormonal secretory activity. Many tumours, particularly smaller lesions, are asymptomatic and found incidentally on imaging done for another indication.
• Larger tumours may present with abdominal distension or a palpable mass and pressure-related symptoms (urinary frequency or bowel symptoms).
• Malignant epithelial tumours presenting at a more advanced stage cause non-specific systemic symptoms, including bloating, early satiety, and weight loss.
• Hormonally active sex cord-stromal tumours present with features of their secretion. Oestrogen-secreting granulosa cell tumours cause precocious puberty or abnormal uterine bleeding. Androgen-secreting Sertoli-Leydig cell tumours cause virilisation (hirsutism, voice deepening, and clitoromegaly). These features are an important diagnostic clue.
• Acute severe pain may reflect ovarian torsion, to which an enlarged ovarian tumour or cyst predisposes mechanically. Less commonly it reflects tumour rupture or haemorrhage. These acute complications need prompt, urgent assessment.

• Pelvic ultrasound is the standard initial imaging investigation. It characterises tumour size, morphology (simple, complex, or solid), and features relevant to risk stratification for malignancy.
• Tumour markers are tailored to the woman's age and the imaging findings. CA-125 is relevant particularly to epithelial ovarian tumours, though non-specific.
• A germ cell tumour marker panel (alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase) is essential when a germ cell tumour is suspected, particularly in children and young women. These markers inform both diagnosis and disease monitoring.
• Magnetic resonance imaging gives additional characterisation where ultrasound is indeterminate or more full preoperative assessment is needed, particularly for larger, more complex, or potentially malignant lesions.
• Definitive histological diagnosis is generally established by surgical excision and pathological examination. Preoperative imaging and tumour markers alone cannot reliably distinguish every tumour subtype or its benign, borderline, or malignant nature.

• Management is directed by tumour type, the woman's age and fertility considerations, and, critically, whether the lesion is benign, borderline, or malignant.
• Benign tumours are managed by surgical excision where intervention is indicated by size, symptoms, or diagnostic uncertainty. Cystectomy preserves normal ovarian tissue where feasible, which matters particularly in younger women wishing to preserve fertility.
• Borderline tumours require surgery. Where fertility preservation is desired, a somewhat more conservative approach than for invasive malignancy is used, given their generally favourable prognosis.
• Borderline tumours need careful surgical staging and structured, longer-term follow-up, because the risk of recurrence or, uncommonly, progression is low but recognised.
• Malignant germ cell tumours are managed with fertility-sparing surgery in appropriately selected early-stage cases: unilateral salpingo-oophorectomy, preserving the contralateral ovary and uterus. This suits their frequently unilateral nature and young patient demographic, in whom fertility preservation is particularly important.
• Higher-stage or higher-risk malignant germ cell tumours also receive adjuvant chemotherapy, given their excellent chemosensitivity and generally favourable prognosis.
• Malignant sex cord-stromal tumours are managed with surgical resection, with the extent individualised by stage and fertility considerations, and adjuvant treatment considered for higher-risk disease.
• Where the subtype secreted hormones, surveillance for hormonal marker recurrence is a valuable addition to longer-term monitoring.
• Malignant epithelial tumours are managed generally with cytoreductive surgery and platinum-based chemotherapy according to stage.
• Individualised counselling on fertility implications and, where relevant, longer-term surveillance planning by tumour type and stage underpin patient-centred management.