Most common presenting feature of retrosternal goitre is?

A goitre is said to be retrosternal if more than half of the thyroid tissue is below the opening of the thoracic cage. It usually arise from the lower pole of the nodular goitre but may also arise from ectopic tissue. It is often symptomless and is discovered during routine chest radiograph. Symptoms may arise due to mass effect on trachea, esophagus, great vessels and nerves. These include: Dyspnea (paicularly at night), cough and stridor Dysphagia Enlargement of neck vein and superficial veins on the chest wall Recurrent nerve palsy Although it is not mentioned anywhere about the most common symptom of retrosternal goitre however as trachea lies in close proximity so mass effect must appear first because of compression of trachea i.e dyspnea. Also know: Pembeon sign: refers to the symptoms of fainting with evidence of facial congestion and external jugular venous obstruction when the arms are raised above head. Ref: Bailey & Love 25/e, page 782