I was recently diagnosed with a mass on my left ovary that is " consistent with a hemorrhagic cyst ". It originally measured 5.7 x 4.0 x 6.9 cm and now measures 3 x 2.5 x 2 cm. Do cancerous ovarian cysts ever get smaller on their own? I read that they only grow and get bigger and never get smaller. It was discovered when I was hospitalized for a Tubo Ovarian Abscess that led to Sepsis.
A mass that is decreasing in size is highly unlikely to be a malignancy. It may be that the tuboovarian abscess is resolving but this requires further follow up with your doctor.