Diabetic mastopathy is an uncommon, benign disease of the breast that can occur in women with diabetes and clinically mimic breast cancer. We describe a patient with long-standing type 1 diabetes who presented with a palpable breast mass with negative imaging findings on mammography, ultrasonography, and breast MRI. Surgical biopsy and histopathology confirmed diabetic mastopathy. We use this case to highlight the recognition, radiographic features, pathology, and management of this benign breast condition and emphasize that, in diabetic patients, the differential diagnosis of a new breast mass should include diabetic mastopathy.
Diabetic mastopathy is an uncommon, benign breast condition, seen in diabetic patients and can masquerade as breast cancer. This diagnostic possibility must be borne in mind during the evaluation of a patient with diabetes and a new breast lump. Soler and Khardori [
Since the original report, only a few hundred case reports/case series have been published in the literature. However, given the often nonspecific or absent radiographic and ultrasonographic features of this condition, it can become a diagnostic dilemma for the physician and a source of great anxiety and concern for the patient. We describe a case of diabetic mastopathy in a Type I diabetic woman to highlight the recognition, management, and pathophysiology of this benign breast condition.
A 33-year-old woman with a long-standing history of insulin dependent diabetes complicated with diabetic retinopathy presented to Breast Clinic for evaluation of a new onset, painless, breast lump. She had incidentally discovered a lump in the upper outer quadrant of the left breast 3 months prior that had gradually increased in size in the interim. She denied breast pain, nipple discharge, or overlying skin changes. With regard to breast cancer risk factors, she was nulliparous, menopausal as she had a hysterectomy for dysfunctional uterine bleeding but ovaries were intact, had no previous history of breast biopsies, and was a nonsmoker. She had no personal or family history of breast or ovarian cancer. Her only medication was a NovoLog insulin pump.
Physical exam was remarkable for a dominant
Imaging evaluations included a diagnostic mammogram that revealed extremely dense breasts. Ultrasound exam of the palpable area was also negative for abnormality. A bilateral MRI of the breast was performed (Figure
MIP image from breast MRI showing multiple regions of enhancement with no mass in the area of clinical concern left breast.
Ultrasound of the palpable abnormality in the left breast shows normal tissue with no mass.
In view of the size and clinically worrisome features of the palpable, yet radiographically occult mass, an excisional breast biopsy was performed to rule out malignancy. Pathology demonstrated benign breast parenchyma, dense stromal fibrosis, and periductal lymphocyte infiltrate suggestive of diabetic mastopathy (Figures
(a) Lymphocytic lobulitis and ductitis with glandular atrophy. Dense fibrosis. (b) Lymphocytic lobulitis, higher magnification.
At her three-month follow-up visit, the patient noted some fullness around her surgical scar that was palpable on clinical breast exam. Diagnostic left breast ultrasound demonstrated a surgical scar, dense breast tissue, but no abnormalities at the area of palpable concern. Continued observation of the breast was recommended with regular clinical followup.
Diabetic mastopathy typically affects premenopausal Type I diabetic women who manifest complications of diabetes, notably retinopathy and neuropathy [
As illustrated by this case, mammography alone, while sensitive for the detection of malignancy, yields no specific features that will result in a diagnosis of diabetic mastopathy. Occasionally, on mammography, regions of asymmetry or ill-defined masses without microcalcifications are associated with the area of palpable concern [
The aforementioned radiographic findings are nonspecific and cannot rule out malignancy, and biopsy is warranted for a definitive diagnosis. Core needle or excisional biopsy is recommended for tissue diagnosis. Fine needle aspiration biopsy is often nondiagnostic in over 50 percent of cases due to scanty cellularity of the aspirate [
Several terms have been used in literature to describe diabetic mastopathy including sclerosing lymphocytic lobulitis, ductitis, stromal fibrosis, and perivasculitis [
Prior reports assessing the pathophysiology of diabetic mastopathy have suggested that it is an immune-mediated disorder, supported by the histopathological findings and B-cell predominance [
Diabetic mastopathy does not incur an increased risk of breast cancer [
Diabetic mastopathy is an uncommon, benign disease of the breast predominantly seen in Type I diabetics that can clinically mimic breast cancer. Imaging modalities including mammography, ultrasound, and breast MRI are largely nonspecific and may not definitively rule out malignancy. Tissue diagnosis using core needle or excisional biopsy of the mass is required to establish a diagnosis. Patients and their clinicians need to be informed that this condition can recur and that any new breast lump needs a complete evaluation to rule out malignancy.
The authors declare that there is no conflict of interests.
The authors appreciate the assistance of the Grant and Publication Support Services within the Department of Medicine, in the preparation and submission of this paper.