What is diabetic mastopathy? How common is it?

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What is diabetic mastopathy? How common is it?

Hi –

I have had Type 1 Diabetes for 35 years. My eldest daughter has had it for 21 years. She is 36 years old. Both of us are looking for information on Diabetic Mastopathy. Two weeks ago she went for a mammogram when she discovered a lump in her breast. The radiologist, GP and surgeon were all convinced that it was cancer and she had scans, a needle biopsy and finally, an op to have the lump removed. I can’t express the feelings of dread with which we faced the 7 days from the mammogram to the final result. When it arrived – we were told that none of them had ever had a patient with this condition and would have to do research etc.

Apparently this condition was only “discovered” in 1980s – in fact there was a woman n the 1990s who had both breasts removed as the doctors believed that she had breast cancer, only to discover that it was in fact Diabetic Mastopathy. I am so angry that no-one gave us any hope during that week and I feel that this condition should be added to the long list of possible diabetic complications that is available to the public. I believe that all diabetic women should be made aware of it, and if they discover a lump – they should immediately see a doctor, but should bring the condition to the radiologist’s and GP’s attention – so many of them don’t know about it.

We would really appreciate any information about this, and if you know anyone else who has been through it. I have just discovered your site and it is amazing!

Thanks so much,





Dear Heather:

What you have said sums up a great deal of what we know about Diabetic Mastopathy. Because the word cancer strikes fear in the heart of the most stalwart, anything that resembles cancer causes a rush of trying-to-help-action that may have varying degrees of actual helpfulness.

The presence of reported Diabetic Mastopathy (DMP) varies by clinic, ranging from 1 in 1,700 women seen in a breast clinic – to - 13% of 20-40 year old type 1 diabetic women attending a diabetic clinic1. What these numbers tell us is the condition is fairly uncommon, greatly unknown among physicians who do not specialize in diabetes, and therefore not regularly noticed, reported or discussed.

DMP is simply a form of fibrous breast tissue (notice I said “tissue”, not “disease”). It causes masses that are hard, painless, irregular in shape, and easily movable as they are not fixated to the skin. By mammography and ultrasound it is indistinguishable from breast cancer2. It becomes more distinguishable by needle biopsy, in that during the back-and-forth motion of the needle, resistance is firmer than other benign and malignant breast conditions3. In addition DMP contains very little cellular material, so a needle biopsy may not gather enough cells for cytological diagnosis.

So how can you differentiate DMP from breast cancer? Good clues lie in taking a careful patient history. It is more often found in pre-menopausal women who have had diabetes from 4 to 27 years4. Often these women may have other diabetic complications such as retinopathy, neuropathy and nephropathy. Or not. In 63% of reported cases, it is bilateral5. Increased family history of breast cancer is not usually seen in women who develop DMP. DMP also has been described in women with type 2 diabetes, as well as other endocrine diseases, especially thyroid diseases6.

What is the best treatment? My grandpa used to say, “If it ain’t broke, don’t fix it.” In the case of DMP the problem is figuring out whether or not it’s “broke”. If your history sounds like the DMP profile, and your mass(es) sound like DMP, it may be possible to have close ultrasound follow up, doing what we call “watchful waiting”5. Approximately 60% of DMP recurs after surgical excision. The recurrence tends to be in the same location, and may involve more breast tissue than the original mass. As such, a needle biopsy under ultrasound guidance would avoid surgery that could worsen the condition.

The most helpful thing for those of us who are diabetic women (or people who care about diabetic women) to know, is that DMP exists. If you know the facts, you can help your physician better understand what the two of you are dealing with, and together you can make healthful, helpful choices.

You’ve inspired me. I sometimes write articles on diabetes for Saturday Evening Post magazine, so I’m going to see if they would be interested in publishing something on Diabetic Mastopathy. Our best offense or defense is education. In addition, you may want to post your note on the Women’s Forum section of DiabetesSister.org to see if other women would like to respond with their stories.



1Errol Wilmshurst, MD. Medical Matters. Facts About Diabetic Breast Disease All Women Should Know. www.diabetesaustralia.com.

2Solar NG, et al. Fibrous disease of the breast, thyroiditis, and cheiroarthropathy in type 1 diabetes mellitus. Lancet 1984;1:193-195.

3Logan WW, et al. Diabetic fibous breast disease. Radiology 1989;172:667-670.

4Seidman JD, et al. Mastopathy in insulin requiring diabetes mellitus. Hum Pathol 1994;25:819-824.

5Camuto PM, et al. Diabetic mastopathy: a report of 5 cases and a review of literature. Arch Surg 2000; 135:1190-1193.

6Ely KA, et al. Diabetic mastopathy: a clinicopathologic review. Am J Clin Pathol 2000;113:541-545.