Which of the following is most common type of ovarian tumors?
**Core Concept**
Ovarian tumors are a heterogeneous group of neoplasms that arise from the ovary, and their classification can be based on their histological origin. The majority of ovarian tumors are epithelial in origin, accounting for approximately 90% of cases.
**Why the Correct Answer is Right**
The most common type of ovarian tumors are epithelial ovarian tumors, which arise from the surface epithelium of the ovary. These tumors can be further classified into serous, mucinous, clear cell, and endometrioid subtypes based on their histological characteristics. The serous type is the most common subtype, accounting for approximately 60-70% of epithelial ovarian tumors. The high incidence of serous ovarian tumors can be attributed to the continuous proliferation of the ovarian surface epithelium throughout a woman's reproductive life.
**Why Each Wrong Option is Incorrect**
**Option A:** Germ cell tumors are a less common type of ovarian tumors, accounting for approximately 2-5% of cases. They arise from the germ cells of the ovary and can be further classified into mature and immature teratomas, dysgerminomas, and yolk sac tumors.
**Option B:** Sex cord-stromal tumors are a rare type of ovarian tumors, accounting for approximately 5-10% of cases. They arise from the stromal cells of the ovary and can be further classified into granulosa cell tumors, Sertoli-Leydig cell tumors, and fibromas.
**Option C:** Metastatic ovarian tumors are a type of ovarian tumors that arise from the metastasis of cancer cells from other parts of the body. They are less common than primary ovarian tumors and can be difficult to diagnose.
**Clinical Pearl / High-Yield Fact**
The risk of developing ovarian cancer increases with age, with the majority of cases occurring in women over the age of 50. Women with a family history of ovarian cancer or BRCA1 and BRCA2 gene mutations are also at increased risk.
**Correct Answer: C. Metastatic ovarian tumors are a type of ovarian tumors that arise from the metastasis of cancer cells from other parts of the body. They are less common than primary ovarian tumors and can be difficult to diagnose.