American Board of Internal Medicine (ABIM) Certification Practice Exam

What should be done if a palpable lump in a patient under 30 is found to have a complex cyst on ultrasound?

1. Wait and observe

2. Perform mammography and FNA or CNBx

3. Refer for surgical excision

4. Aspirate the cyst

The correct answer is: Perform mammography and FNA or CNBx

In patients under 30 years of age with a palpable lump that is found to be a complex cyst on ultrasound, the appropriate course of action is to perform mammography and fine needle aspiration (FNA) or core needle biopsy (CNBx). This approach is chosen due to several factors associated with complex cysts. Complex cysts may contain both cystic (fluid-filled) and solid components, which raises concern for the potential presence of malignancy. While complex cysts can represent benign conditions, the risk of breast cancer increases with certain characteristics seen on ultrasound, such as the presence of solid components or irregular borders. Mammography can help evaluate the extent of any further abnormalities in the breast and is an important screening tool in assessing breast lumps. Performing FNA or CNBx allows for cytological or histological analysis of the solid portion, ensuring that any suspicious cells are identified. This step is crucial, particularly in younger patients where the risk for breast cancer, while lower than older patients, has not been ruled out. Waiting and observing might lead to a missed diagnosis if there were an underlying malignancy. Surgical excision may be considered if there is a high suspicion of cancer based on imaging or biopsy results, but it's generally not the first step