Double primary adenocarcinomas of the jejunum and descending colon with lung metastases presenting rare immunohistochemical phenotypes: a case report.

We report a male patient with double advanced tumors in the jejunum and descending colon and multiple lung tumors. The intestinal cancers were surgically resected. Immunoprofiling of the specimens revealed a rare phenotype: the jejunal cancer was positive for cytokeratin (CK) 7, partially positive for CK20, and Cdx-2-negative, whereas the colon cancer was CK7(+), CK20(-), and Cdx-2(-). Biopsied lung tumor was diagnosed as tubular adenocarcinoma, and CK7(+)/CK20(+)/Cdx-2(-). Together with clinical information, we deduced that the jejunal adenocarcinoma had presumably metastasized to the lung. Moreover, postoperative oxaliplatin, including chemotherapy, significantly reduced the lung metastases, suggesting that this regimen is a promising treatment option for advanced small bowel adenocarcinoma.