Differential Diagnosis for Ovarian Cysts

The patient presents with a 2 cm clear septated cyst on the left ovary, which has remained unchanged in size, along with a new 1.7 cm x 1.3 cm septated cyst on the same ovary. The CA125 levels are within normal limits, and previous imaging studies have not shown any suspicious features. Based on this information, the following differential diagnoses can be considered:

• Single Most Likely Diagnosis
  • Benign Ovarian Cysts: The presence of clear septated cysts with no solid components, stable size over time, and normal CA125 levels makes benign ovarian cysts the most likely diagnosis. The fact that the cysts have not changed in size and have a simple appearance on imaging suggests a low risk of malignancy.
• Other Likely Diagnoses
  • Functional Ovarian Cysts: The patient's age and the presence of follicular changes on the CT scan suggest that the cysts could be functional in nature, related to hormonal fluctuations.
  • Serous Cystadenomas: These are common benign ovarian tumors that can present as septated cysts, similar to what is seen in this patient.
• Do Not Miss Diagnoses
  • Ovarian Cancer: Although the likelihood is low, ovarian cancer must be considered, especially in a postmenopausal woman. The presence of septations and the development of a new cyst warrant further evaluation to rule out malignancy.
  • Borderline Ovarian Tumors: These tumors have a lower malignant potential than ovarian cancer but can still cause significant morbidity if not diagnosed and treated promptly.
• Rare Diagnoses
  • Mucinous Cystadenomas: These are rare benign ovarian tumors that can present as large, septated cysts.
  • Dermoid Cysts: Although typically seen in younger women, dermoid cysts can occur in postmenopausal women and may present as complex ovarian masses.

It is essential to note that while the likelihood of ovarian cancer is low, given the patient's age and the presence of septated cysts, further evaluation by a Gyn Oncologist is warranted to rule out malignancy. The patient's CA125 levels are within normal limits, but this marker is not foolproof, and imaging characteristics are not definitive for benignity. Therefore, a thorough assessment, potentially including surgical evaluation, may be necessary to determine the nature of these ovarian cysts.