Mediastinal Cystic Teratoma in a Patient From Papua: A Rare Case Report.

Mediastinal teratomas are rare benign germ cell tumours that develop between the lungs, representing approximately 1%-5% of all mediastinal tumours. This case report presents a 41-year-old male patient from Papua with a history of chronic cough for 3 months and fatigue for about a month. Physical examination revealed decreased breath sounds in the right upper lung field, while laboratory tests were normal. A chest CT scan identified a benign cystic mass in the right anterior inferior mediastinum. Trans-thoracic CT-guided fine-needle aspiration with ROSE cytology suggested an infected cyst content that may be part of a cystic teratoma or a bronchogenic cyst. Separately, a transbronchial lung biopsy revealed histology consistent with chronic inflammation. The patient declined intervention and returned to Papua. This case highlights the challenges in managing patients who decline standard treatment, particularly those from remote areas, and emphasises the importance of patient education regarding the potential complications of untreated mediastinal teratomas.