Objectives: To present a case of primary pulmonary epithelioid trophoblastic tumor co-existing with Choriocarcinoma in an otherwise asymptomatic reproductive-aged multigravida and include a detailed description of the histopathologic findings and review literature as to the incidence, presentation, diagnosis, management and outcome of these patients.

Background: Epithelioid trophoblastic tumor (ETT) is a rare type of gestational trophoblastic neoplasia (GTN) arising from intermediate trophoblasts of the chorion leave. The most common symptom is vaginal bleeding (57-67%) associated with an endomyometrial mass mostly seen in the lower uterine segment and the cervix (71%). A review of literature showed that rarely, it can present in extrauterine sites most commonly in the lungs and in other sites like the small bowel, vagina, fallopian tube, broad ligament and the gall bladder. Primary Extrauterine ETT co-existing with Choriocarcinoma is even a more uncommon occurrence as it is mostly reported in patients clinically diagnosed to have Gestational Trophoblastic Neoplasia (GTN) who presented with chemoresistance after several courses of chemotherapy.

Case: ETT is initially diagnosed in a 28year old G5P4 presenting with a nodular opacity in the left middle lobe after a routine chest x-ray which showed interval progression in size even after antibiotic treatment. Transvaginal ultrasound was normal. Beta hCG remained low at 33.48 – 59.7 mIU/ml. A video assisted left upper lobectomy was done after which beta hCG determinations remained normal on follow-up. Histopathology and Immunohistochemistry were consistent with Epithelioid Trophoblastic Tumor with co-existing Choriocarcinoma elements.

Conclusion: A diagnosis of ETT should be considered in a reproductive-aged woman presenting primarily with a lung mass with no referable symptoms and pathology in the reproductive tract. A detailed histologic review should be done, including immunohistochemistry, to be able to diagnose rare cases of Mixed GTN.

Elizabeth K Jacinto has completed her subspecialty fellowship training in Trophoblastic Diseases at the University of the Philippines-Philippine General Hospital (UP-PGH). She has served as the Chief of the Division of Trophoblastic Diseases for 17 years, since 2006. She is also a founding member and Past President of the Philippine Society for the Study of Trophoblastic Diseases.