Simultaneous cutaneous melanoma and ipsilateral breast cancer with metastasis to the same axilla. A case report with a focus on a multidisciplinary approach

Introduction and importance: Treatment of simultaneously occurring primary malignancies with separate lymphatic drainage is a surgical and medical challenge. We present a patient in which multidisciplinary management of coexisting melanoma and breast cancer was mandatory for optimal results.Case presentation: A 67-year-old female had a primary surgical resection for a skin lesion on the back. Histology revealed melanoma with a Breslow thickness of 4.8 mm. According to guidelines, a wide local excision was scheduled. Prior to the surgery, routine mammography revealed simultaneous ipsilateral breast cancer. A preoperative work-up revealed a pathological lymph node in the left axilla. Biopsies found metastasis from malignant melanoma. She had combined surgery with breast-conserving therapy, wide local excision of the skin on the back, and extended axillary clearance of levels I-III. Final histology revealed axillary metastases both from melanoma and breast cancer. Adjuvant therapy was decided based on a multidisciplinary approach.Clinical discussion: To our knowledge, cases of synchronous primary cutaneous melanoma with biopsy-verified axillary metastases and independent, ipsilateral primary breast carcinoma have not been described. The surgical approach was done according to guidelines. The breast cancer was re-staged based on the histology of the surgical specimen. Adjuvant treatment was a combination of treatment strategies for the two primary malignancies.Conclusion: This case highlights the need for a multidisciplinary approach in treating simultaneous breast cancer and melanoma both with axillary metastasis. The optimal treatment approach was based on close collaboration between surgeons, oncologists, radiologists, and pathologists. Multidisciplinary meetings are mandatory for optimal results.