Eyelid swelling: think of metastasis of histiocytoid breast carcinoma.

Metastatic breast carcinoma may assume many clinicopathological patterns. We here describe a case of histiocytoid breast carcinoma metastasis in the eyelids of a 73-year-old woman. Clinically, the patient presented painless swelling and nodular infiltration of the lateral and medial portions of the eyelids recalling a xanthomatous process or cystic lesions. Physical examination revealed similar lesions on the neck and right thigh. Medical history had revealed breast carcinoma 5 years previously. A biopsy specimen taken from a nodule on the eyelids revealed a relatively symmetric dermal tumor composed mainly of large, uniform, round-to-oval cells embedded in a fibrous stroma with moderate mucin deposits. The cells had abundant, coarsely granular eosinophilic cytoplasm and scant or absent nuclear atypia. No lobular arrangement of the cells or overt ductal formation were seen. Only occasional intracytoplasmic lumina were observed. Most cells demonstrated a positive immunoreaction for carcinoembryonic antigen. It is important to recognize histiocytoid breast carcinoma metastasis in the eyelids, because it may easily be overlooked clinically and histopathologically. This tumor should not be confused histopathologically with other benign and malignant skin tumors containing similar granular cells, but which have a different significance or a different prognosis. The immunohistochemical study, in conjunction with the medical history of the patient, facilitated the diagnosis.