Metastatic Esophageal Carcinoma Masquerading as Inflammatory Breast Carcinoma

Abstract

Metastasis to the breast from extramammary neoplasms is rare. Such metastatic neoplasms can mimic inflammatory breast carcinoma clinically and histologically, presenting a diagnostic challenge. A 50‐year‐old woman with a history of esophageal adenocarcinoma in clinical remission presented with rapid onset unilateral breast swelling with warmth and erythema. Based upon the clinical presentation, an underlying breast carcinoma was suspected. A punch biopsy revealed a poorly differentiated adenocarcinoma with extensive involvement of the dermal lymphatics. The clinical and histologic differential diagnosis included inflammatory carcinoma secondary to a primary breast carcinoma vs. metastatic esophageal adenocarcinoma to the skin of the breast. To resolve this question, immunohistochemical stains for estrogen and progesterone receptors and CDX‐2 were performed. CDX‐2 is an intestinal homeobox gene that is expressed in intestinal epithelium and tumors with intestinal differentiation including esophageal adenocarcinoma. CDX‐2 expression has not been reported in breast carcinoma. The tumor cells were positive for CDX‐2 but negative for both steroid receptors. The diagnosis of metastatic esophageal adenocarcinoma to the skin of the breast was confirmed. This case emphasizes the importance of confirming the tumor lineage in inflammatory carcinoma of the breast. CDX‐2 can be a useful tool in establishing a gastrointestinal origin of cutaneous metastases.