Lymphedema of the breast as a symptom of internal diseases or side effect of mTor inhibitors.

A common situation presented in any clinical facility is a woman with swelling and redness of the breast. Diagnosis upon suspicion is often mastitis or inflammatory breast cancer, which are popular and well-known diseases of the breast. However, there is one main differential diagnosis which has to be taken into consideration: lymphedema of the breast. Twenty patients with internal diseases presented in our Breast Care Unit over a 4-year period with breast-affecting lymphedema. The patients suffered from cardiac failure, nephrotic syndrome, liver failure, lymphadenopathy, and central vein occlusion. Additionally, we identified 5 patients with a history of organ transplantation and under immunosupressive medication with sirolimus or everolimus. These mTor inhibitors are known to have unwanted side effects such as unilateral or bilateral upper/lower extremity peripheral edema or facial/eyelid edema, but as we know, isolated lymphedema of the breast represents a previously unreported complication.