A case of malignant eccrine spiradenoma metastatic to intramammary lymph node.

Eccrine spiradenoma (ES) is a fairly common, benign, cutaneous tumor originating from the sweat glands. In contrast, the malignant counterpart of ES, malignant eccrine spiradenoma (MES), is extremely rare. A long-standing lesion rarely begins to enlarge rapidly. A growth that results in ulceration or discoloration may be associated with malignant transformation. We present the first reported case of this tumor metastasizing to an intramammary lymph node (IMLN). The uncommon metastasizing focus of the periumbilical MES and its histopathological similarity with a primary breast carcinoma made the diagnosis difficult.