A rare clinical case of malignant ectopic retrosternal goiter of a large size in a patient with aberrant right subclavian artery

Background. Ectopic goiter accounts for only 0.2 % to 1 % of all mediastinal goiters. The aberrant right subclavian artery (arteria lusoria) is an extremely rare anomaly of the major vessel, with a prevalence not exceeding 0.3 % in the general population. This paper presents the first case of malignant ectopic retrosternal goiter of a large size in combination with the aberrant right subclavian artery. Clinical case description. A 61-year-old male presented to the thoracic surgery department of P. Herzen Moscow oncology Research institute with a large posterior mediastinal mass measuring 108×106×79 mm and adjacent to the right lobe of the thyroid gland. The tumor displaced the trachea and esophagus. Open biopsy through a thoracotomy incision revealed thyroid gland cells without signs of atypia. A detailed examination revealed mediastinal vascular anomaly – retrotracheal position of the right subclavian artery. a complete longitudinal sternotomy, complemented by a right-sided thoracotomy at the 3rd intercostal space, served as the surgical approach. The operation lasted 320 minutes, with a blood loss of 3500 ml. The postoperative period was uneventful. The morphological examination of the surgical specimen revealed nodular hyperplasia of the ectopic thyroid tissue with the growth of well-differentiated follicular carcinoma without metastatic involvement of removed lymph nodes. Considering the identified follicular carcinoma, total thyroidectomy was performed. Conclusion. In surgical planning, it is crucial to assess the location of major mediastinal vessels and their relationship with the goiter. Therefore, all patients with mediastinal lesions should undergo preoperative contrast-enhanced ct. Retrosternal goiter predisposes to a higher rate of malignancy compared to cervical goiter. If the lower edge of the goiter is at the level of or below the aortic arch, cervical access should be supplemented with sternotomy. In cases of a massive thoracic component, additional thoracotomy is justified.