Which one of the following is NOT an epithelial tumour of the ovary: September 2012
**Core Concept**
Epithelial ovarian tumors are a group of neoplasms derived from the ovarian surface epithelium, which is a layer of epithelial cells covering the surface of the ovary. These tumors are the most common type of ovarian cancer, accounting for approximately 90% of cases.
**Why the Correct Answer is Right**
Epithelial ovarian tumors can be classified into several subtypes, including serous, mucinous, clear cell, and endometrioid carcinomas. These tumors arise from the ovarian surface epithelium and can be influenced by genetic and environmental factors. The correct answer is not one of these subtypes, which are all epithelial in origin.
**Why Each Wrong Option is Incorrect**
**Option A:** Serous carcinoma is a type of epithelial ovarian tumor that arises from the ovarian surface epithelium.
**Option B:** Mucinous carcinoma is another subtype of epithelial ovarian tumor that also arises from the ovarian surface epithelium.
**Option C:** Clear cell carcinoma is a rare but aggressive type of epithelial ovarian tumor that also originates from the ovarian surface epithelium.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that epithelial ovarian tumors are the most common type of ovarian cancer, and they can be classified into several subtypes based on histological features. A high index of suspicion and early detection are crucial for improving outcomes in patients with epithelial ovarian cancer.
**Correct Answer:** D.