Zosteriform cutaneous metastasis of breast carcinoma in a male patient

a male patient Editor, A 62-year-old man was referred to our outpatient clinic for the evaluation of a gradually enlarging papulonodular asymptomatic eruption of six months duration involving the right lower part of the trunk. Clinical examination revealed the presence of multiple coalescent, red to violaceous, indurated nodules and papules in a dermatomal distribution, along the T4–T7 neurotomes, at the lower right side of the thorax (Fig. 1a). A full body examination uncovered a subtle ipsilateral retraction of the nipple, firmly attached to a palpable tumor located beneath the areola. Furthermore, ipsilateral palpable axillary and supraclavicular lymph nodes were detected. The patient’s medical history was unremarkable. Under the clinical suspicion of metastatic skin disease, we performed an incisional skin biopsy. Histological examination showed the dermal invasion of adenoid neoplastic cells compatible with metastatic carcinoma of the breast (Fig. 1b). Subsequent fine needle aspiration cytology of the breast mass was consistent with carcinoma of the breast. Further laboratory examination revealed bone and lung metastases; the patient was diagnosed with stage IV breast cancer and treated accordingly. Cutaneous metastasis from an internal malignancy is a relatively frequent manifestation and is reported to occur in 5–10% of malignancies. In the vast majority of cases, it represents a sign of disease progression and is characterized by a wide array of clinical presentations. Breast cancer is the neoplasia most commonly associated with skin metastases. However, the arrangement of skin lesions in a dermatomal distribution is highly unusual: only 10 cases of zosteriform cutaneous metastasis related to breast carcinoma have been published in the literature. To the best of our knowledge, this is the first reported case of a dermatomal cutaneous metastasis originating from breast carcinoma in a male patient. From a morphological perspective, dermatomal metastatic skin disease usually (in seven of 10 published cases) manifests with solid papulonodular lesions, as in our patient. Vesicobullous lesions have been reported in only three individuals. In addition to breast carcinoma, other primary malignancies associated with zosteriform patterns of skin metastases include melanoma, systemic and cutaneous B cell and T cell lymphomas, respiratory, gastrointestinal, and urinary tumors, and angiosarcoma and Kaposi’s sarcoma. Possible explanations for the zosteriform spread of cancer cells in the skin include vascular (lymphatic or hematogenous) spread, neural spread, the surgical implantation of malignant cells in the skin, and Koebnerization at the site of previous herpes zoster. Given that our patient had not undergone any surgical procedures before the development of the cutaneous metastasis, and his medical history was negative for herpes zoster, we suggest that