High-grade serous carcinoma is a type of ovarian cancer characterized by rapidly growing cancer cells. It typically originates in the ovaries but can also affect the fallopian tubes and peritoneum. This cancer is known for its aggressive nature and is often diagnosed at an advanced stage, making treatment more challenging. The cancer cells in high-grade serous carcinoma appear abnormal under a microscope, indicating a high level of malignancy. Common symptoms may include abdominal swelling, pain, and changes in bowel habits. Treatment usually involves a combination of surgery and chemotherapy to manage the disease effectively.