Well-differentiated fetal adenocarcinoma of the lung: clinicopathologic features of 45 cases in China.

Objective: Well-differentiated fetal adenocarcinoma (WDFA) is a rare pulmonary carcinoma with low malignancy and favorable prognosis. All cases were collected, analyzed and summarized to better understand this disease.

Methods: We used the keywords "fetal adenocarcinoma" and "epithelial pulmonary blastoma (EPB)" to search WANFANG MED ONLINE, CNKI and NCBI PUBMED for cases reported by Chinese authors from 1987 to July 2015.

Results: A total of 64 cases reported in China were reviewed, and the details of the clinicopathological features of 45 cases were summarized. Among these 45 patients, 23 (23/45, 51.1%) patients were male and 22 (22/45, 48.9%) patients were female. The mean age at diagnosis was 35 ± 15 years old (range, 6-72 years old) with a bimodal peak in the second and third decades. Furthermore, 24 tumors (24/31, 77.4%) were found to have progressed past stage I, while only three (3/45, 6.7%) tumors had lymph nodes metastases. These tumor cells were 100% reactive for keratin, β-catenin, Napsin A and PDGFRα when stained by these antibodies. Better survival could be obtained if the metastatic tumor is removed in some patients with metastases. Four (4/31, 12.9%) patients died due to their tumors.

Conclusions: WDFA is very different to conventional adenocarcinoma in clinicopathology. It prefers to occur in the second and third decades. Lymph node metastasis is infrequent. Beta-catenin may be a potential marker for disease. Surgery is the best therapy method if the technology is feasible.