Indocyanine green guided resection of a mediastinal teratoma: A case report

Mediastinal teratomas present unique surgical challenges during resection. Here, we describe a novel use of Indocyanine Green (ICG) for real time identification of tumor borders and resection planes of a malignant mediastinal teratoma and right lung nodule. A 13-year-old male with Klinefelter's Syndrome presented for right upper quadrant pain, difficulties walking and eating, and with elevated alpha-fetoprotein (AFP) and beta human chorionic gonadotropin (β-hCG). A CT scan demonstrated a lobulated right-sided mediastinal mass, as well as an isolated right middle lobe lung nodule. The patient underwent elective resection. He was injected with 3 mg/kg ICG one day prior to his planned operation. After median sternotomy, ICG imaging aided in the identification of the mediastinal mass, tumor borders and resection planes, particularly where the tumor was continuous with the right lobe of the thymus and along the deeper structures of the mediastinum. The right lung nodule was similarly visualized and resected. Pathologic examination of the mass revealed components of immature teratoma, choriocarcinoma, yolk sac tumor, and seminoma. The lung nodule demonstrated only chronic inflammation and compressive atelectasis from the tumor's mass effect. The patient recovered well and was discharged on post operative day 6. He follows with the oncology team for outpatient chemotherapy. Though rare, teratomas in the mediastinum can occasionally be malignant and have the potential to involve adjacent structures, thereby creating a technical challenge at surgery. This case demonstrates the usefulness of ICG for intraoperative visualization of tumors to facilitate safe resection and improved outcomes.