The heart's struggle for space: a unique case of gigantic mediastinal mass compression

SESSION TITLE: Unexpected Airway Abnormalities SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/09/2023 09:40 am - 10:25 am INTRODUCTION: Primary mediastinal germ cell tumors (PMGCTs) are rare and aggressive tumors that account for 1-3% of all germ cell tumors (GCTs) 1,2. Based on histology, GCTs are divided into seminomas and non-seminomas. Mixed GCTs constitute a rare subset of non-seminoma GCTs and carry an overall poor prognosis 2,3. PMGCTs are usually diagnosed in young adults and present with symptoms due to mass effect. We present a rare case of PMGCT presenting as a massive mediastinal mass. CASE PRESENTATION: A 22-year-old male with an unremarkable medical history presented with several months of progressive dyspnea and cough. He was treated with antibiotics for presumed pneumonia. However, his respiratory symptoms quickly worsened. Chest Computed tomography (CT) demonstrated a 24x14x19cm anterior mediastinal mass causing massive compression of the left hemithorax and nearby cardiovascular structures. This lead to the displacement of the heart and great vessels. He had elevated serum lactate dehydrogenase, alpha-fetoprotein, and beta human chorionic gonadotropin. CT guided biopsy of the mass showed mixed germ cell tumor. Scrotal ultrasound revealed no evidence of testicular mass. Due to airway compression by the tumor, his respiratory status continued to decline requiring intubation. Flexible bronchoscopy revealed extrinsic compression of the airway with 70% obstruction of the distal trachea and 90 % obstruction of the left mainstem. Under fluoroscopic guidance, an 18x60mm covered metallic stent was deployed in the trachea and a 14x40mm covered metallic stent was placed in the left mainstem. The patient's respiratory mechanics subsequently improved. After two cycles of platinum-based chemotherapy, repeat imaging demonstrated slight improvement in tumor burden with a large area of tumor necrosis within the mass. Thoracic surgery evaluated him for resection but he was deemed too high risk for surgery. Patient continued to have worsening hemodynamics and eventually died. DISCUSSION: This case demonstrates a rare tumor presenting as a massive mediastinal mass. While PMGCTs are known to cause mass effect this can complicate management. Standard treatment includes platinum-based chemotherapy followed by local therapy with either tumor resection or radiotherapy 2,3. In cases when tumor is causing airway compromise, a covered metallic stent can be safely considered and deployed in the airways to stabilize patient's respiratory status. Despite appropriate treatment, non-seminoma PMGCTs remain difficult to treat with a poor prognosis compared with gonadal GCTs and seminoma PMGCTs. Overall survival rate remains less than 50% 1,2,3. CONCLUSIONS: This rare case highlights the challenges in managing a massive mediastinal mass caused by a PMGCT. Despite platinum-based chemotherapy and airway stenting, the patient's prognosis remained poor, emphasizing the need for early recognition and aggressive intervention in similar cases. REFERENCE #1: Kumar N, Madan R, Dracham CB, et al. Primary mediastinal germ cell tumors: Survival outcomes and prognostic factors - 10 years experience from a tertiary care institute. Rare Tumors. 2020;12:2036361320972220. Published 2020 Nov 18. doi:10.1177/2036361320972220. REFERENCE #2: Pini GM, Colecchia M. Mediastinal germ cell tumors: a narrative review of their traits and aggressiveness features. Mediastinum. 2022 Mar 25;6:5. doi: 10.21037/med-21-22. PMID: 35340833; PMCID: PMC8841550. REFERENCE #3: Marandino L, Vogl UM. Mediastinal germ cell tumours: where we are and where we are going-a narrative review. Mediastinum. 2022 Mar 25;6:7. doi: 10.21037/med-21-33. PMID: 35340835; PMCID: PMC8841536. DISCLOSURES: No relevant relationships by Stephanie Baltaji No relevant relationships by Danai Khemasuwan No relevant relationships by Ashley Reluzco Consultant relationship with COOK medical Please note: $1001 - $5000 by Ray Shepherd, value=Consulting fee Removed 03/31/2023 by Ray Shepherd, source=Web Response Royalties - authorship relationship with UpToDAte Please note: $1001 - $5000 by Ray Shepherd, value=Royalty grant for industry study relationship with Olympus Spiration Please note: $1001 - $5000 by Ray Shepherd, value=Grant/Research Support grant clinical trial relationship with GALA therapeutics Please note: 2022 to present Added 03/31/2023 by Ray Shepherd, source=Web Response, value=Grant/Research Support