Dear Dr. Roach: I was diagnosed with several liver cysts over 15 years ago. My primary doctor and I follow the growth of the cysts by ultrasound, and one is increasing in size. We did an MRI with and without contrast to take a look at the cyst. The radiologist stated that the cyst looked “complex” and, for a lack of a better word, unusual.

A liver specialist’s consult revealed that we could remove it if I wanted to. The doctor stated he just had a patient who had a cyst, and it was a cancerous cyst. He felt that it may be best to remove it, but it’s not urgent to do so.

I would appreciate your take on this situation.

— L.S.

Answer: Simple liver cysts are common, and even when they are large, they do not need to be removed unless they cause symptoms. However, any cyst other than a simple one needs to be carefully evaluated, since there are many possibilities including various types of cancer, especially a mucinous cystic neoplasm, which can be associated with invasive cancer.

I looked at both the ultrasound and MRI reports you sent, and although it seemed to me that the radiologists thought this was likely a simple cyst with some bleeding, they could not be sure. Furthermore, the growth in the size of the cyst is concerning.

In some cases, it’s reasonable to wait and redo the scans in 6-12 months when the risk of a cancerous cyst is low. However, since the liver specialist (who has much more experience than I do) is concerned enough to recommend surgery, I don’t understand why you would want to wait. I suspect the surgery will prove that it was a benign cyst, but you’ll probably sleep better at night once you know for certain.

The surgery is normally done laparascopically, and although it’s usually a very safe and effective surgery, there is always a small risk for complications. You should speak with a surgeon.

Dear Dr. Roach: Do you have any comments on the use of metformin for weight loss and prediabetes? I am a 57-year-old woman.

— B.S.

Answer: That’s one question I can answer based on very good data. The National Diabetes Prevention Program looked at this very issue. Subjects in the study, who averaged 51 years of age and were overweight with prediabetes, were treated with metformin; an intensive lifestyle-behavioral-change program that aimed for a low-fat diet and 150 minutes of exercise per week; or a placebo.

The diet and exercise group had the best response, decreasing the rate of new diabetes by 58%, compared to the placebo group. However, the metformin group also had a benefit, with a 31% decrease in the rate of new diabetes diagnoses.

Personally, I recommend both. Metformin does help a bit with weight loss, but taking it along with some diet changes and exercise would likely have a much better response than metformin alone. We don’t recommend a low-fat diet much anymore, emphasizing whole fruits and vegetables, whole grains, and very few processed foods. A registered dietician would be a valuable partner in helping with the diet of your regimen. You don’t need to exercise for the whole 150 minutes, but it’s a goal you can work toward.

New studies show that drugs like semaglutide are even more effective at preventing diabetes, but they are very expensive and often not covered by insurance.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.