Ovarian pathology can be a bit of a maze because there are so many different cell types involved! Since you're prepping for the UKMLA AKT, it's really important to distinguish between the benign "functional" cysts we see in younger patients and the more concerning features of malignancy.

Let's break this down into the classification, the role of CA-125, and how we decide on surgery.

1. Classification of Ovarian Masses

We generally divide these into Functional (Benign) and Neoplastic (which can be benign, borderline, or malignant).

• Functional Cysts: Very common in premenopausal women.
  • Follicular cysts: The most common; occur when a follicle fails to rupture.
  • Corpus luteum cysts: Occur when the corpus luteum fails to involute.
• Neoplastic Tumours: Classified by the cell of origin:
  • Surface Epithelial (90% of cancers): Serous (most common), Mucinous, Endometrioid, Clear cell.
  • Germ Cell: Often seen in younger women. Includes Dermoid cysts (Mature Cystic Teratoma) and Dysgerminomas.
  • Sex Cord-Stromal: Fibromas (associated with Meigs' syndrome), Sertoli-Leydig, or Granulosa cell tumours (which can secrete oestrogen).

2. CA-125 and the Risk of Malignancy Index (RMI)

In the UK, we don't just look at CA-125 in isolation. For postmenopausal women with an ovarian cyst, we calculate the Risk of Malignancy Index (RMI), which combines three factors:

1. CA-125 level
2. Menopausal status
3. Ultrasound features (e.g., multilocular cysts, solid areas, metastases, ascites, bilateral lesions).

==An RMI score > 200 is the typical threshold for referral to a specialist multidisciplinary team (MDT) for suspected cancer.==

Note on CA-125: It’s notoriously non-specific in premenopausal women! It can be raised by endometriosis, PID, fibroids, or even pregnancy.

3. Surgical Approach

The choice between Laparoscopy (keyhole) and Laparotomy (open) depends heavily on the suspicion of malignancy.

• Laparoscopy: The gold standard for benign-appearing cysts (like dermoids or simple cysts) in premenopausal women. It offers faster recovery and less pain.
• Laparotomy: Preferred if there is a high suspicion of malignancy (high RMI) or if the mass is too large/complex. The goal here is often full staging and cytoreduction (debulking).

I'll pull up some high-yield lessons and a flowchart to help you visualize the management pathway for these cysts.