INFECTED MEDIASTINAL MATURE TERATOMA

Abstract

TOPIC: Disorders of the Mediastinum TYPE: Medical Student/Resident Case Reports INTRODUCTION: Mature teratoma, a benign germ-cell tumor, commonly presents in the ovaries. Extragonadal manifestation is uncommon and rarely occurs with superimposed infection. We present a unique case of extragonadal teratoma found in the mediastinum complicated by infection. CASE PRESENTATION: A 24-year-old male with a history of asthma presented with a 3-day history of dyspnea and right rib pain radiating into the center of his chest. He reported a 30-pound weight loss in the preceding 3 months. He denied tobacco, alcohol, or recreational drug use. He previously worked as a coal miner but is now working in coastal drilling. He was afebrile and normotensive but had an oxygen saturation of 93% on room air. On examination, he had right upper lobe rhonchi with absent breath sounds in the right basilar region. Chest imaging showed complete collapse of the right middle and lower lobes, large loculated right pleural effusion within the anterior right lung base, and heterogeneity with rim enhancing fluid collection, which was suggestive of empyema. The patient had leukocytosis of 16.6k with neutrophil predominance of 14.18k. The patient was started on empiric intravenous antibiotics with vancomycin, ceftriaxone, and metronidazole. He underwent video-assisted thoracoscopic surgery with cystic mass resection from the pericardial surface and anterior surface of right lower lobe, 1600 milliliters of purulent fluid drainage, and decortication of right middle and lower lobes. Frozen section showed squamous and glandular cells. Pathology showed keratinized skin with granulation tissue, acute and chronic inflammation, and giant cell reaction consistent with infected mature teratoma. Pleural fluid's gram stain revealed 2+ PMNs and no growth in aerobic, anerobic, fungus, or AFB cultures. The patient was de-escalated to amoxicillin-clavulanate for a 14-day course and clinically improved. DISCUSSION: This case demonstrates a rare presentation of extragonadal mature teratoma in the mediastinum. Mediastinal teratomas occur from 20 to 40 years old with clinical symptoms of cough, chest pain, trichoptysis, and fever. Possible complications are infection, rupture, malignant transformation, and paraneoplastic anti-N-methyl-D-aspartate receptor (anti-NMDA receptor) associated limbic encephalitis. Infected mature teratomas are uncommon. Reported infectious organisms include Salmonella enterica, Escherichia coli, Mycoplasma pneumonia, Staphylococcus aureus, Staphylococcus agalactiae, and Haemophilus influenza. Proposed pathogenesis is due to the release of proteolytic enzymes from pancreatic and/or intestinal mucosal tissues in the tumor leading to inflammation and eventual infection. CONCLUSIONS: Teratoma rarely presents with superimposed infection, which may be complicated by rupture. Definitive management is surgical excision of teratoma and antibiotic targeting the organism. REFERENCE #1: Lee WL, Yen MS, Tseng JY, Yu KW, Wang PH. Mature teratoma with secondary infection: case report. Changgeng Yi Xue Za Zhi. 1999 Jun;22(2):339-43. PMID: 10493045. REFERENCE #2: Li C, Lin F, Liu C, Hai Y, Liu L. Intrapulmonary teratoma misdiagnosed as aspergilloma. Thorac Cancer. 2018;9(2):328-329. doi:10.1111/1759-7714.12566 REFERENCE #3: Tian Z, Liu H, Li S, et al. Surgical treatment of benign mediastinal teratoma: summary of experience of 108 cases. J Cardiothorac Surg. 2020;15(1):36. Published 2020 Feb 17. doi:10.1186/s13019-020-1075- DISCLOSURES: No relevant relationships by Ashley Anselene, source=Web Response No relevant relationships by Asma Balobaid, source=Web Response No relevant relationships by Shu Xian Lee, source=Web Response No relevant relationships by Rebecca Reece, source=Web Response