My mother was diagnosed with breast cancer in 2008. She had a lumpectomy, (3 lymph nodes were taken out, but only one of them were positive) chemotherapy and then radiation. The tumor had both estrogen and progesteron receptors, but no HER2 receptors. Therefore, she gets hormone treatment. She started to take tamoxifen in last September. (The US before the treatment didn't show anything in the ovaries.) At the end of September, she had other examinations (as tamoxifen reduce the risk of breast cancer, but it increases the risk of uterine cancer and so forth..) The US examination showed something in her right ovary. Then there was an MR examination. The result was: Atypical ovarian cyst, it is needed to be controlled. The cyst mainly contains fluid, but it has a soft / semi-solid part. Since September, she has had more examinations in order to monitor the cyst and make sure that nothing has changed. Fortunately, nothing has changed since September, so it didn't get larger, it didn't change in look, it didn't grow, it's the same. However, my mum's oncologyst still worries, because of the semi-solid part. A very experinced gyncologist examined my mum, he took a look on the cyst, but he couldn't decide wether it is malignant or benign. He told my mum that only surgery and biopsy can decide it. Nobody had ovarian cancer in our family, even not breast cancer. We are still worried. My mother'll have a surgery in April. (Her ovaries will be taken out)
Is an atypical ovarian cyst malignant (if it didn't change)? Can it be benign (if if didn't grow) ? Can tamoxifen cause such a cyst?