Gigantic mammary Paget's disease of a very elderly woman.

BACKGROUND: Recently, surgical stress due to breast cancer has been reduced, more so for elderly patients. However, an expanded resection is still required in some situations.

CASE PRESENTATION: We present a case of a 90-year-old woman with a 15 × 15 cm2 erythema and localized skin ulceration with hemorrhage in her right breast. A punch biopsy indicated mammary Paget's disease. Computed tomography showed that the tumor was only located on the surface of the breast with no metastasis, including of the axillar lymph nodes. We decided to perform surgery with sufficient informed consent. We performed muscle-sparing mastectomy with sampling of an axillar lymph node, adding two stress-relaxation sutures to avoid diastasis. The patient's postoperative course was good. A histological examination revealed mammary Paget's disease without invasion and no evidence of a residual tumor of the entire stumps. Her quality of life was improved after surgery.

CONCLUSION: Mammary Paget's disease has a relatively good prognosis. However, advanced mammary Paget's disease leads to a decrease of quality of life with symptoms such as skin ulcer and bleeding. Surgery should be performed in such cases, considering the risks and benefits, even in older patients with comorbidities.