Diabetic mastopathy of bilateral breasts in an elderly Japanese woman with type 2 diabetes: a case report and a review of the literature in Japan.

We report a case of diabetic mastopathy in an elderly woman with type 2 diabetes. The patient was a 69-year-old woman diagnosed with type 2 diabetes at the age of 33 years. She had been treated with insulin for 25 years, however, her blood glucose had been poorly controlled. She noticed bilateral breast lumps in September 2002. Mammography of the breast showed increased density in the glandular pattern and architectural distortion without focal mass and microcalcification. Ultrasonography of the breast showed an irregular-shaped hypoechoic mass with an acoustic shadow. As malignancy needed to be excluded, core needle biopsy was performed in the left breast and diabetic mastopathy was confirmed pathologically. Diabetic mastopathy is usually a complication of pre-menopausal type 1 diabetes and develops in a unilateral breast. This case developed in bilateral breasts in an elderly type 2 diabetic patient.