Zosteriform Cutaneous Metastasis from Breast Cancer: A Case Report

Introduction: Cutaneous metastases are observed in approximately 10% of oncology patients, often indicating either a persistent solid tumor or the recurrence of neoplastic disease. The most prevalent cause of cutaneous metastases in females is breast cancer. Patients with breast cancer may exhibit cutaneous manifestations at the initial diagnosis; however, these metastases more frequently emerge well after the initial diagnosis and treatment. The cutaneous lesions resulting from metastatic breast carcinoma display considerable variability in appearance. Typically, they manifest as firm, flesh-colored to red, smooth or ulcerated, or crusted nodules, papules, and plaques on the ipsilateral chest wall and breast. Additionally, unusual sites for breast cancer cutaneous metastases include the eyelids, inframammary folds, ipsilateral lymphedematous arm, scalp, subungual nail bed, and umbilicus. Skin metastases can also occur in mastectomy scars and radiation therapy ports. Several distinct patterns of skin metastases are recognized in breast cancer patients: carcinoma erysipelatoides, carcinoma telangiectoides, and carcinoma encuirasse. Recently, carcinoma hemorrhagiectoides has also been documented. The pleomorphic nature of breast cancer metastases can mimic various benign and malignant conditions, such as collision tumors, cysts, dermatofibromas, milia-en-plaque, melanoma, non-melanoma skin cancers, cellulitis, folliculitis, herpes zoster, paronychia, erythema annulare centrifugum, urticaria, alopecia areata, dermatitis, hidradenitis suppurativa, scleroderma, angiokeratoma, angiosarcoma, lymphangioma circumscriptum, purpura, and pyogenic granuloma. Consequently, it is crucial to consider the possibility of cutaneous metastasis from breast cancer in any patient, whether previously diagnosed with breast cancer or not, who presents with new or treatment-resistant cutaneous lesions. Confirmation of the diagnosis necessitates a biopsy of the skin lesion. ...........