Ectopic Mediastinal Thyroid: A Crossroad Between a Multi-Layered Endocrine Perspective and a Contemporary Approach in Thoracic Surgery

An ectopic thyroid (ET) involves numerous scenarios of detection and outcomes, while its current management is not standardised. A mediastinal ET (MET) represents a low index of suspicion. In this paper, we introduce a 47-year-old female who was accidentally identified with an MET, and a modern surgical approach was provided. An anterior mediastinal mass of 3.2 cm was found at CT upon a prior COVID-19 infection. Previous to the infection, she experienced non-specific complaints for a few months (intermittent night sweats, facial erythema, chest pressure, and dyspnoea). Also, CT identified a thymus-like mass and a left adrenal incidentaloma of 3 cm. The endocrine panel was normal, and the subject declined further investigations. She was re-admitted 12 months later: the MET had increased +1 cm (+45% volume) and was confirmed at a 99mTc pertechnetate scintigraphy. Noting the symptoms, mediastinal anatomy, and size change, the MET was removed via a minimally invasive trans-cervical approach (eutopic gland preservation) with the help of a Cooper thymectomy retractor (which also allowed for a synchronous thymus mass resection). No post-operatory complications were registered, the thyroid function remained normal, and the mentioned symptoms were remitted. A histological exam confirmed a benign MET and thymus hyperplasia, respectively. To conclude, this case pinpoints important aspects, such as the clinical picture became clear only upon thoracic surgery due to the complete remission of the complaints that initially seemed widely non-specific. The incidental MET finding was associated with a second (adrenal) incidentaloma, a scenario that might not be so rare, following multiple imaging scans amid the COVID-19 era (no common pathogenic traits have been identified so far). The co-presence of a thymus mass represented one more argument for surgery. Minimally invasive cervicotomy associated with eutopic gland conservation and the use of a Cooper thymectomy retractor highlight modern aspects in video-assisted thoracic surgery, which provided an excellent outcome, involving one of the lowest mediastinal thyroids to be removed by this specific procedure. Awareness of such unusual entities helps inform individualised, multidisciplinary decisions for optimum prognoses.