Breast Cancer Metastasis Misdiagnosed as an Angiokeratomatous Eruption. An Infrequent Presentation. Case Report.

INTRODUCTION: Cutaneous metastases represent 2% of all metastases. Breast cancer is the most common cause of skin metastases. Schwartz described 8 types of cutaneous breast metastases; one uncommon form is carcinoma telangiectodes (CT), which may resemble angiosarcoma or lymphangioma circumscriptum. However, there are no reports of CT misdiagnosed as eruptive angiokeratomas.

CASE REPORT: The authors describe the clinical, histopathologic, and immunohistochemical features of a unique case of CT. Clinical examination revealed an itchy, dark blue-reddish scaly papular eruption that resembled angiokeratomas. The papules were grouped in a zosteriform pattern on the right chest. A biopsy of the papules revealed intravascular thrombi of neoplastic cells and erythrocytes. The neoplastic cells were pleomorphic and with mitotic figures. Immunohistochemical analysis revealed expression of HER-2-neu in neoplastic cells but negative for estrogen and progesterone receptors. The involved vessels were positive for CD31 and negative for podoplanin. This immunoprofile demonstrated intravascular spread of aggressive breast carcinoma.

CONCLUSION: CT is an uncommon form of cutaneous metastasis from breast carcinoma with less than 10 cases described in the literature. There are no previous reported cases of CT mimicking angiokeratomas, although lymphangioma circumscriptum-like lesion may occasionally resemble angiokeratomas. A unique clinical presentation of CT is described.