FES avid pulmonary adenocarcinoma and confounding ER+ breast carcinoma.

Breast carcinomas are well known for expression of estrogen receptor (ER) however there are other malignancies that are also express ER, possibly confounding the diagnostic interpretation of 16α-[F]fluoro-17β-estradiol (FES; Cerianna GE HealthCare) in patients with both ER+ breast carcinomas and other malignancies. We present a case of a woman with prior history of both ER+ breast carcinoma and pulmonary adenocarcinoma with subsequent identification of an FES pulmonary nodule that was proven on histopathology to be consistent with an ER expressing pulmonary adenocarcinoma metastasis.