Synchronous resection of pulmonary metastases from pancreatic carcinoma with lepidic growth that required differentiation from pulmonary mucinous and primary pulmonary adenocarcinomas: A case report

Abstract

Background. The incidence rate of multiple cancers is now increasing due to the improvement of treatments, the development of medical technology, and aging. Case. A 75-year-old woman had a history of surgical resection of pancreatic carcinoma. During the follow-up, abnormal shadows on the lung field were observed. Chest computed tomography revealed a mass 10 mm in diameter with relatively clear borders and ground-glass patterns in the right S2, and small round masses 5 mm in diameter in the right S5 and S8. A partial resection was performed for the three lung masses. A histopathological examination revealed that the mass in S2 had lepidic tumor growth and resembled Clara cells. It was diagnosed as non-mucinous adenocarcinoma in situ. In contrast, while the masses in S5 and S8 also showed lepidic tumor growth, they had large numbers of columnar cells with mucin production and a shift of the nucleus to the basal side. To differentiate pulmonary mucinous adenocarcinoma from metastases of pancreatic adenocarcinoma, a mutation analysis of KRAS was performed. A KRAS gene mutation (G12D) was detected in the primary pancreatic carcinoma and the tumors in S5 and S8. Conclusion. We encountered a case of synchronous resection of pulmonary metastases of pancreatic carcinoma with lepidic growth that required differentiation from pulmonary mucinous and pulmonary adenocarcinomas.