Ovarian tumours are commonly arise from
**Core Concept**
Ovarian tumors can arise from various cell types within the ovary, including epithelial, stromal, and germ cells. The most common type of ovarian tumor is epithelial in origin, accounting for approximately 90% of all ovarian neoplasms.
**Why the Correct Answer is Right**
Epithelial ovarian tumors arise from the surface epithelium of the ovary, which is composed of a single layer of cuboidal or columnar cells. These tumors can be benign, borderline, or malignant and are often associated with a family history of breast or ovarian cancer. The majority of epithelial ovarian tumors are serous in type, followed by mucinous and clear cell tumors.
**Why Each Wrong Option is Incorrect**
**Option A:** Germ cell tumors are less common, accounting for approximately 2-5% of all ovarian tumors, and typically present in younger women.
**Option B:** Stromal tumors arise from the connective tissue of the ovary and account for about 5-10% of all ovarian tumors, often presenting as large masses.
**Option C:** Sex cord-stromal tumors are a rare group of ovarian tumors that arise from the sex cords and stroma, accounting for less than 5% of all ovarian tumors.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that epithelial ovarian tumors are the most common type, and serous tumors are the most prevalent subtype. A family history of breast or ovarian cancer increases the risk of developing epithelial ovarian cancer.
**Correct Answer:** D.