Duodenal Metastasis in Triple-Negative Invasive Ductal Breast Carcinoma With Negative Mammography: A Case Report and Review of the Literature

Abstract

Breast cancer metastasis to the gastrointestinal tract is uncommon, and duodenal involvement is exceptionally rare. Those cases that do metastasize are reported to be lobular, with ductal carcinomas comprising only a small percentage of reported cases. Furthermore, these invasive carcinomas are typically estrogen receptor-, progesterone receptor-positive ± human epidermal growth factor receptor 2 malignancies. We present a unique case of a patient with duodenal metastasis as the first sign of metastatic breast cancer. The rarity of this case is highlighted by the fact that the patient had no known breast malignancy, and pathological findings revealed triple-negative invasive ductal carcinoma consistent with primary breast cancer. Diagnostic mammogram and ultrasound were negative for any lesions.

Figure 1.

Contrast-enhanced computed tomography scan of the abdomen and pelvis with (a) coronal view and (b) axial view revealing bulky mesenteric and retroperitoneal adenopathy with segments of small bowel wall thickening

Figure 2.

Esophagogastroduodenoscopy revealing a semicircumferential necrotic and fragile mass in the second portion of the duodenum (a and b).

Figure 3.

Histologic staining with hematoxylin and eosin from the duodenal biopsy shows (a) invasive ductal carcinoma with mitosis (×20) and (b) malignant cells surrounded by tumor necrosis (×10).

Figure 4.

Immunohistochemical staining from the duodenal biopsy was (a) positive for cytokeratin 7 (×10), (b) negative for cytokeratin 20 and caudal type homeobox transcription factor 2 (×10), (c) positive for GATA binding protein 3 (×10), and (d) negative for estrogen, progesterone, and human epidermal growth factor receptor 2 (×10).

Figure 5.

Diagnostic mammogram of (a) right and (b) left breast revealing no evidence of malignancy.