Background: Cutaneous metastases of a primary malignancy are a rare skin lesion differential diagnosis. We present the case of metastatic breast cancer arising as a cutaneous skin lesion of the right lower back and survey the literature surrounding this.

Methods: Written consent was obtained from the patient.

Results: A 73-year-old female presented with a cutaneous lesion on her right lateral lower back 22 years following her treatment for ductal adenocarcinoma of the left breast. The lesion was a 10mm x 6mm in size, erythematous, nodular, non-painful and not pruritic. The patient had an excisional biopsy which revealed a dermal nodular deposit of adenocarcinoma consistent with a cutaneous metastatic recurrence. She was managed in a multidisciplinary team environment and is currently undergoing second-line systematic therapies. Cutaneous metastases account for approximately 2% of all skin malignancies with breast cancer the most common malignancy to metastasize to the skin. For breast cancer patients, cutaneous metastases are often suggestive of a poor prognosis ; identification of these skin lesions is often associated with a mean survival of only 3 months. 

Conclusion: Metastatic malignancy recurrence presenting as a cutaneous lesion remains a rare event and could represent a visible sign of disease progression.  Our case and literature review emphasize the importance of longtitudinal, multidisciplinary care for cancer patients. Clinician's treating skin cancer should consider a broad differential diagnosis therefore for patient's with even a distant history of malignancy as in the case presented particuarly when the lesion carries atypical features.