Mature teratomas of the ovary belong to a benign lesion; however, if a malignant transformation occurs, its growth rate will increase. As the tumor volume enlarges, it can cause women to experience heaviness and even pain on one side of the lower abdomen, and some women may also experience symptoms of lumbar discomfort. When its volume enlarges and compresses ovarian tissue, it can affect the function of the ovaries, leading to menstrual irregularities, anovulation, and difficulties in conception. Some women may experience the torsion of the teratoma pedicle, inducing acute abdominal pain, especially after sudden changes in body position or urination. Furthermore, when the teratoma undergoes malignant changes and becomes significantly large, it can also compress surrounding organs causing corresponding symptoms. For instance, compression towards the front can affect the bladder, causing frequent urination, whereas compression towards the back can impede bowel movement in the rectum. Sometimes, it can also compress nerves in the pelvic wall, causing pelvic pain.