Diabetic mastopathy (DMP) are noncancerous lesions in the breast most commonly diagnosed in premenopausal women with type 1 diabetes. The cause of this condition is unknown. Symptoms may include hard, irregular, easily movable, discrete, painless breast mass(es).
Diabetic mastopathy is the occurrence of lymphocytic mastitis and stromal fibrosis in men as well as women having long-standing diabetes. Clinical and radiological appearance can raise a suspicion of malignancy and result in unnecessary biopsy. As these lesions are known to recur; failure to recognise them can have devastating results. A case of diabetic mastopathy is therefore presented for the knowledge and benefit of all so that unnecessary surgery can be avoided.
Common symptoms of diabetic mastopathy include hard, irregular, easily movable, discrete, painless breast mass(es). This condition can involve one or both breasts and can affect males and females. The breast lesions may not be palpable in some individuals. Individuals with diabetic mastopathy who have had insulin-requiring diabetes for a long time (>15 years) commonly have other diabetes complications as well (e.g., thyroid, eye, and joint involvement).
The cause of diabetic mastopathy is unknown. Theories include an autoimmune reaction, genetic factors such as human leukocyte antigen (HLA) type, association with insulin therapy, and association with hyperglycemia.
The diagnosis of diabetic mastopathy should be considered in patients with long-standing insulin-dependent diabetes and a firm, mobile breast mass. Initial imaging studies may include mammography and ultrasound. While these methods can help to further differentiate the mass, they cannot provide a specific diagnosis of diabetic mastopathy with confident exclusion of malignancy. A core biopsy (utilizing a needle to remove a small cylinder of tissue) is often performed for a definitive diagnosis.
An accurate diagnosis of diabetic mastopathy is important to avoid unnecessary surgeries.
If you can feel lumps in the breast, you should see your doctor urgently, even if you have previously ignored any lumps and attributed them to diabetes, as breast cancer is much more common than diabetic mastopathy.
This can be done effectively using a core biopsy which establishes whether the lumps are malignant. This procedure allows tissue to be removed from the breast without the need for surgery.
Otherwise, an HbA1c test may be administered to assess the glucose control of people with diabetes and whether they are at risk of complications such as diabetic mastopathy.
Relationship with type 1 diabetes
Diabetic mastopathy is predominantly found in patients with type 1 diabetes, but its cause is largely unknown. Generally, it is believed to be due to an autoimmune process.
Rachel Gifford, CDE reports that 13% of pre-menopausal women with type 1 diabetes develop diabetic mastopathy.
A widely reported aspect of diabetic mastopathy details that patients will likely have other diabetes-related complications beforehand.
These could include kidney disease or neuropathy, while J. Andrew Keyoung, MD et al report that patients may also have eye, thyroid and joint problems.
Relationship with type 2 diabetes
A theory by JE Tomaszewski et al observed that type 2 patients with diabetic mastopathy were exposed to exogenous insulin, which may be related to the development of the condition.
Similarly to with type 1, however, while diabetic mastopathy has been described in women with type 2 diabetes, there is a lack of scientific evidence to identify a cause.
Typically, no treatment is necessary for diabetic mastopathy. Individuals with this condition should be advised about the condition and how to self examine the breasts to detect any changes in size and number of breast lumps. Patients should be routinely followed up with MRI or ultrasound and core biopsy if the lesions become clinically or radiologically suspicious. Lesions can be surgically removed for cosmetic reasons or if malignancy cannot be excluded.
The reported prevalence of DMP ranges from 0.6% to 13% in women with type 1 diabetes. It is a rare entity and is typically seen as a self-limiting fibro-inflammatory disease of the breast. In many patients with DMP; other associated complications arising from diabetes such as retinopathy, neuropathy and nephropathy have also been noted.1 Fortunately our patient had no such associated complications of diabetes.
DMP has also been reported in patients with type 2 diabetes as well as those with thyroid diseases. Rarely, diabetic men too can have DMP.
On palpation the patients often have firm, mobile, painless palpable, unilateral or bilateral breast masses. Such findings can raise the suspicion of malignancy. Our patient had a firm, mobile and painless mass in her right breast.
X-ray mammography shows a localised increased density, with or without any distinct masses, spiculation or calcifications. Posterior acoustical shadowing from the palpable breast masses is the hallmark on sonomammogram, which was also seen in our case. This is said to occur due to the fibrotic nature of the lesions. As clinical and radiological imaging features are not specific of DMP, many times it is not possible to differentiate a benign mass from a malignant one without biopsy.6, 7
The firm resistance experienced during the back-and- forward motion of the needle while performing fine needle aspiration cytology is stronger than that of other benign and malignant breast conditions; and serves as a clue to the diagnosis of DMP.8 The ductal epithelium shows no signs of malignancy and typically has dense, hyalinised fibrous tissue.
Adipose tissue as well as cellular material is markedly absent or barely minimum. There are focal periductal, perivascular, and perilobular lymphocytic infiltrations with mature B-cell predominance. Epitheloid fibroblasts in the interlobular stroma may also be seen. Our patient too had similar pathological findings.
As DMP is known to recur after surgical removal, it should better be avoided. The pathogenesis of DMP is supposed to be due to a secondary autoimmune reaction to abnormal extracellular matrix accumulation arising from the effects of hyperglycemia on connective tissue. Glycosylation induced by hyperglycemia, increases intermolecular cross-linkage and matrix expansion of altered quality and quantity which resists degradation. The triggered autoimmune response manifests with autoantibody production and B-cell proliferation.
As reports on DMP have been few, no standard protocol exists for the long-term management of these patients. Hence annual follow-up by imaging studies would be useful in identifying the progression and detection of other abnormalities at the earliest.
To the best of our knowledge malignant transformation of these lesions has never been reported although, there has been a reported case of regression of this entity. The current literature does not reveal any relationship between the duration and severity of the diabetes and extent of the mammary lesion. Moreover no change in the size of the lesion has been found either with proper or even with poor control of the diabetic status of the patient.
No active management is needed as majority of the patients are usually asymptomatic. Symptomatic medications for pain relief may be offered. There is a role of proper counselling to remove the fear of possible cancer that prevails in the mind of every female with a lump in breast. Periodic annual follow-up mammography has a good scope in addressing these issues. Excisional biopsy is the only way out for patients who are highly concerned about this unwanted breast lump. It must, however, be remembered that approximately 60% of such lesions tend to be bilateral or recur after surgical excision.2 As the recurrence is usually in the same location and involves a larger area than it earlier was; the surgical biopsy should better be avoided. Moreover, in addition to ipsilateral; bilateral and even contralateral recurrences are known.
In the past, it had been suggested that newer lesions in known diabetic mastopathy patients be assessed by fine-needle aspiration rather than biopsy if the clinical and imaging features are inconclusive or suspicious of malignancy.
But the current consensus on diagnostic procedures is on ultrasound-guided diagnostic breast biopsy technology which is now believed to be the most minimally invasive technique for evaluation of indeterminate and suspicious lesions seen on diagnostic breast ultrasound.10 Modern research has shown that the 8-gauge vacuum-assisted biopsy approach to ultrasound-guided diagnostic breast biopsy appears to be advantageous to that of the spring- loaded 14-gauge core biopsy approach for providing the most accurate and optimal diagnostic information.10 But nevertheless, one must keep in mind the disadvantages of a fine needle biopsy like the issue of the adequacy of tissue sampling and sampling from the appropriate representative area. A proper sample alone can minimise the risks for mis-estimation of any given breast finding and for reducing the risks of false negative results for finding a lesion to be due to diabetic mastopathy or to be due to breast carcinoma.
Whenever clinico-cytological features are consistent with diabetic mastopathy, conservative clinical management and close follow up should be considered.
To summarise, knowledge about this rare entity and a careful clinico-imaging-pathological correlation in the clinical setting of diabetes mellitus helps identify this condition and avoids unnecessary surgical biopsies, mental distress as well as the diagnostic uncertainty.