Pulmonary well-differentiated fetal adenocarcinoma with platelet-derived growth factor receptor (PDGFR)α expression.

Well-differentiated fetal adenocarcinoma (WDFA) is a rare pulmonary malignancy. Biomarkers of tumor biology has rarely been studied in WDFA. Here, we report two WDFA patients. Both patients had blood-streaked sputum or mild hemoptysis at presentation. They underwent lobectomy and systematic mediastinal lymphadenectomy. Expression of PDGFRα on the plasma membrane was demonstrated by immunohistochemistry (IHC) in the resected tumor specimens. Further IHC examination showed intense immunostaining of β-catenin in both patients but negative staining for TP53, CEA, CD56, EGFR, CK5/6, HER2, S-100, ER, PR, BCL2, and NSE. Both patients had no recurrence to date after more than 3 years of follow up. Herein, we reviewed this rare disease with special emphasis on the clinico-pathological features, treatment and potential role of PDGFRα.