Main types: serous and mucinous cystadenomas
Papillary serous cystadenoma is of the greatest clinical significance due to its high risk of malignant transformation. Unlike smooth-walled forms, its surface epithelium actively proliferates. Two types of growth are distinguished:
- Inverting: papillary growths form large nodes inside the capsule.
- Everting: papillae grow through the capsule outward, giving the ovary a "cauliflower-like" appearance. This form is more severe, is more frequently bilateral, and is accompanied by ascites twice as often.
Mucinous (pseudomucinous) cystadenoma ranks second in frequency. It is a benign tumor characteristic predominantly of postmenopause.
- Macroscopically, these are almost always multilocular giant formations.
- Inside the chambers is mucus (mucin containing glycoproteins).
- The inner lining is represented by tall columnar epithelium, very similar to the cells of cervical glands. Papillary structures are uncharacteristic of a true mucinous tumor.
Rare and mixed forms
Rare epithelial neoplasms include pseudomyxoma and Brenner tumor.
Pseudomyxoma of the ovary and peritoneum develops upon the rupture of the wall of a mucinous tumor (or appendix), or when its wall is infiltrated with mucus. Mucus freely accumulates in the abdominal cavity between the loops of the intestine. The tumor does not infiltrate the underlying tissues, but the process has an extreme tendency to recur, leads to severe body wasting, and carries a serious prognosis. The main treatment is surgical evacuation of the mucus.
Brenner tumor (fibroepithelioma) accounts for about 2% of all ovarian neoplasms. Macroscopically, it is a dense node without a distinct capsule, resembling a fibroma in appearance and consistency. Microscopically, it consists of epithelial nests surrounded by strands of spindle-shaped cells. Cellular atypia and mitoses are absent.
Also encountered are mixed tumors, combining serous and mucinous structures in the form of multilocular formations with various contents.
Clinical presentation and complications
Benign epithelial tumors have no specific reliable symptoms. The disease is often asymptomatic and is detected in women over 40–45 years of age.
- Pain syndrome: dull, aching pain in the lower abdomen, groin, or lower back, radiating to the lower extremities. As a rule, it is not associated with the menstrual cycle. In papillary cystadenomas pain appears earlier due to bilateral involvement and adhesive disease in the pelvic cavity.
- Compression syndrome of adjacent organs: urinary disorders (pressure on the bladder), constipation, noticeable increase in abdominal volume (especially with giant mucinous cystadenomas).
- Complications: torsion of the tumor pedicle or capsule perforation causes sharp pain and the clinical picture of an "acute abdomen." In addition, every fifth patient experiences impaired reproductive function (primary or secondary infertility), and menstrual irregularities are the second most common complaint.
Diagnostic methods
The basis of the physical examination is bimanual vaginoperitoneal and rectoabdominal examinations.
Bimanually, the physician assesses the size, consistency, and mobility of the formation. For example, a simple serous cystadenoma is palpated as a smooth, elastic formation 5–10 cm in size, while a mucinous one is felt as a nodular tumor up to 20 cm or more. The informative value of palpation drops sharply in cases of obesity, adhesions, or extremely small or giant sizes of the cystadenoma.
Rectovaginal examination is critical for ruling out a malignant process. It makes it possible to detect "spikes" in the posterior fornix, bulging of the fornices (a sign of ascites), and tumor invasion into the rectum.
Ultrasonography (US) allows a detailed study of the internal structure:
- Papillary cystadenomas: uneven parietal papillae of increased echogenicity are visible (sometimes with lime deposits), giving the wall a rough or spongy appearance.
- Mucinous cystadenomas: visualized as huge multilocular formations with multiple thick septa and echogenic suspension.
- Brenner tumor: on the echogram, it often mimics a subserous uterine myoma.
Briefly: answers to topical questions
What complications can occur with benign epithelial ovarian tumors?
Benign epithelial ovarian tumors may lead to:
- Torsion of the tumor pedicle (partial or complete) — paroxysmal or acute pain, clinical picture of an "acute abdomen."
- Capsule perforation — acute pain, clinical picture of an "acute abdomen."
- Malignancy transformation — the most serious complication of papillary serous cystadenomas; the rate of malignant transformation reaches up to 50%.
- Ascites — in papillary serous cystadenomas due to the proliferation of papillae along the peritoneum and impairment of the resorptive capacity of the peritoneum.
Which tumor markers are used for the differential diagnosis of epithelial ovarian tumors?
Tumor markers are used for the differential diagnosis of benign and malignant ovarian tumors, although most of them are non-specific.
- CA-125 — normal up to 35 IU/mL; detected in 78–100% of ovarian cancer patients; should not be used as a screening test
- HE4 — used together with CA-125 and in the ROMA algorithm
- CA-19.9
- CA-72.4
- Additionally, the RMI and ROMA indices are used.
To memorize the forms of papillary cystadenoma: Everting — papillae grow exophytically (outward, like a cauliflower), runs extremally (more severely, ascites is more frequent). Inverting — papillae grow intracapsularly (inward).
Class and exam questions
What is the main difference between borderline cystadenoma and ovarian cancer?
In a borderline tumor (both serous and mucinous), there is a strict absence of tumor epithelial invasion into the underlying stroma, despite the presence of nuclear polymorphism and increased mitotic activity.
Why does ascites frequently occur in papillary serous cystadenomas?
Ascites develops due to the proliferation of papillae along the peritoneum and the surface of the tumor itself, as well as due to impaired resorptive (absorptive) capacity of the peritoneum of the rectouterine pouch.
Why is a rectovaginal examination mandatory when an ovarian tumor is suspected?
It is necessary to rule out malignant growth: it allows detecting specific "spikes" in the posterior fornix, bulging of the fornices in the accumulation of ascetic fluid, and tumor invasion into the mucous membrane of the rectum.
What else to study on this topic
- Ultrasonic features of smooth-walled (simple) serous cystadenoma
- Differential diagnosis of Brenner tumor and subserous uterine myoma
- Pathogenesis and sources of development of pseudomyxoma peritonei
- Causes of the "acute abdomen" clinical picture in ovarian cystadenomas
- Limitations of bimanual examination in giant tumors and adhesive disease
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