The final pathology report on the left corpus luteum cyst located a small focus of moderately differentiated adenocarcinoma in corpus luteum staining strongly positive for Cytokeratin 7 (CK7) and negative for Cytokeratin 20 (CK 20) suggesting a primary gastric or pancreatic carcinoma. This evidence concerns the gene KRT7 and exocrine pancreatic carcinoma.