|Home | About | Journals | Submit | Contact Us | Français|
Organs commonly affected by diabetes mellitus include retina, kidneys and peripheral nerves. Involvement of the breast is unusual.
A man of 47 sought advice because of below-knee numbness and brief loss of consciousness after a fall from a bicycle. Non-insulin-dependent (type 2) diabetes had been diagnosed 4 years earlier and he was being treated with glibenclamide and metformin. He was also hypertensive. Random plasma glucose was 15 mmol/L. On examination there was no neurological deficit but a firm, freely mobile, painless, non-tender, subareolar lump was felt in the left breast. The patient said it had been present for six months. Fine needle aspiration of the mass yielded a haemorrhagic non-representative sample, so a lumpectomy was performed with the provisional diagnosis of gynaecomastia.
The mass measured 4 × 2.5 × 2 cm and was firm and white on the cut surface. Microscopy showed a lesion with extensive keloid-like fibrosis along with many epithelioid fibroblasts. A lymphocytic ductitis was also present, together with a dense perivascular lymphocytic infiltrate (Figure 1). An absence of lobules was consistent with this being a male breast. The lesion fulfilled the criteria of diabetic mastopathy.
In 1984, Soler and Khardori1 reported a fibrosing mastopathy in patients with longstanding type 1 (insulin-dependent) diabetes mellitus who had other complications of diabetes. Subsequently the term diabetic mastopathy was given to lesions exhibiting a perivascular lymphocytic infiltrate in addition to fibrosis. Tomaszewski et al.2 proposed that the presence of epithelioid fibroblasts in addition to keloidal fibrosis, lobulitis, ductitis and vasculitis was specific for this condition. Most of these lumps have been described in women and have been associated with longstanding type 1 diabetes. There have been rare reports in men and in patients with type 2 diabetes. A similar condition has also recently been reported in the absence of diabetes.3
The pathogenesis of this condition is unknown. A proposed autoimmune reaction is consistent with the development of similar lesions in patients with systemic lupus erythematosus and hypothyroidism.1,4 Tomaszewski et al. suggested that the lesion might be the result of hyperglycaemia-induced collagen deposition. The production of advanced glycosylated end products, with resultant neoantigen formation and subsequent B-lymphocyte proliferation and cytokine release, leads to matrix expansion.2
The histological appearances are characteristic and pose little difficulty in diagnosis provided one is aware of this uncommon entity. However, epithelioid fibroblasts can be prominent and abundant enough to mimic infiltrating carcinoma cells.4 There is no documented increase in carcinoma or lymphoma of the breast in these patients.5 Ely et al.3 have shown a high incidence of bilaterality and of ipsilateral and contralateral recurrences; thus, in a recurrence these patients can be safely followed-up without further surgical biopsy. Fine needle aspiration is not a satisfactory way to monitor these patients because about half the lesions are too fibrous to be aspirated.6
Our patient was unusual in that, apart from being a man, his diabetes was type 2 and of short duration, he had no other complications of diabetes, and he was taking oral antidiabetic agents. A history of diabetes or a raised blood glucose should alert clinicians to the possibility of diabetic mastopathy.