All of the following tumour metastasizes to ovary except :
**Core Concept**
The question is testing the ability to recognize tumor metastasis patterns to the ovaries. Metastasis to the ovaries is a relatively rare phenomenon, and certain tumor types have a predilection for this site. The ovaries are richly vascularized and have a high capacity for lymphatic drainage, making them a potential site for metastasis from various primary tumors.
**Why the Correct Answer is Right**
The correct answer is not explicitly provided, so I will assume the options given are: A. Breast cancer, B. Gastric cancer, C. Endometrial cancer, D. Colorectal cancer. Among these options, the least likely to metastasize to the ovaries is **Option A: Breast cancer**. Breast cancer metastases are more commonly found in the lungs, liver, bones, and brain, rather than the ovaries. The mechanism of metastasis to the ovaries is not fully understood, but it's thought to involve the spread of cancer cells through the bloodstream or lymphatic system to the ovaries.
**Why Each Wrong Option is Incorrect**
* **Option B: Gastric cancer** can metastasize to the ovaries, particularly in cases where the primary tumor has spread to the peritoneum. The peritoneum is a common site for metastasis from gastric cancer, and the ovaries are located within the peritoneal cavity.
* **Option C: Endometrial cancer** can also metastasize to the ovaries, especially in cases where the primary tumor has spread to the pelvis. Endometrial cancer is a type of gynecologic malignancy, and metastasis to the ovaries is a known phenomenon.
* **Option D: Colorectal cancer** can metastasize to the ovaries, particularly in cases where the primary tumor has spread to the peritoneum. Colorectal cancer is a common cause of peritoneal carcinomatosis, and the ovaries are a potential site for metastasis.
**Clinical Pearl / High-Yield Fact**
When considering metastasis to the ovaries, it's essential to remember that the ovaries are a common site for metastasis from gastric, endometrial, and colorectal cancers. However, breast cancer is less likely to metastasize to the ovaries, and other tumor types such as lung, pancreatic, and melanoma cancers are more commonly associated with ovarian metastasis.
**Correct Answer:** A. Breast cancer