When There Are a Myriad of Causes, and It's the Rarest One: A Case Report of Mediastinal Teratoma

Lymphadenopathy and chest pain are frequent reasons for consultation in primary health care, with a myriad of possible etiologies, ranging from infections to malignancy. When these symptoms persist or present with warning signs, longitudinal reassessment, progressive integration of clinical findings, and appropriate investigation become essential for diagnosis. A case is presented of a 40-year-old man of Nepalese origin who was first seen in 2015 for cervical lymphadenopathy associated with odynophagia in the context of tonsillitis. Despite partial improvement after adequate treatment, the patient maintained lateral cervical and supraclavicular lymphadenopathies and did not return for follow-up. He returned in 2017 due to persistent lymphadenopathies and occasional episodes of retrosternal pain and a feeling of pressure in the lower throat, losing follow-up once again afterward. Between 2021 and 2023, he continued to have similar episodes, developing chest pain with pleuritic characteristics. Several etiologies were considered, and the corresponding tests and treatments were performed, without relevant changes or symptom remission. In December 2023, the patient underwent a thoraco-abdominopelvic computed tomography (CT) scan that revealed an anterior mediastinal mass with adjacent lymphadenopathy, raising concern for malignancy. He was urgently referred to hospital care and underwent a biopsy that revealed a mature teratoma. In 2024, surgical excision was performed via video-assisted thoracoscopic surgery (VATS), revealing adhesion to the pericardium and proximity to the phrenic nerve and brachiocephalic venous trunk. The patient progressed with complete remission of symptoms. This case highlights the importance and possible complexity of continuity of care, of the assessment of persistent signs and symptoms, and of the temporal integration of clinical findings, which are fundamental for the identification of rare diagnoses, such as mediastinal teratoma, even in situations of low adherence to the care plan.