'Forgotten' goitre after total thyroidectomy

'Forgotten' goitre (FG) is a mediastinal portion of the thyroid found after total thyroidectomy. It is extremely rare.

To report on 5 cases and review the literature.

We retrospectively reviewed all patients with retrosternal goitre at Mohammed V Military Teaching Hospital, Rabat, Morocco, from 1 January 2010 to 31 December 2020 and identified 5 patients who underwent surgery for forgotten mediastinal goitre during this period. Data on patient characteristics, time of the first thyroidectomy, imaging (chest radiograph, chest computed tomography (CT) scan and magnetic resonance imaging), surgical approach, pathological findings and postoperative complications were collected.

Five patients (3 female and 2 male) with a mean age of 46.2 years (range 32 - 56 years) with FG had surgery. Two patients were asymptomatic and 3 patients had dyspnoea, 2 of whom also had dysphonia and 1 signs of hyperparathyroidism. No patient had a history of thyroid cancer. The average time between the first thyroidectomy and re-operation was 4.3 years. The diameter of the masses on CT scan was 7 - 12 cm. All the patients underwent sternotomy. Postoperative transitory left recurrent laryngeal nerve palsy occurred in 1 case. There were no postoperative deaths. Pathological examination of the mediastinal goitre confirmed multi-heteronodular thyroid hyperplasia in all cases.

FG is an extremely rare condition, which can be prevented with thorough preoperative imaging.

What the study adds. 'Forgotten' goitre is a mediastinal portion of the thyroid found after total thyroidectomy. It is extremely rare. We report on 5 cases.Implications of the findings. Thorough preoperative imaging of retrosternal goitre can prevent the occurrence of forgotten goitre and its associated morbidities. Sternotomy is usually required for reoperation, highlighting the importance of complete initial thyroidectomy.