GENERAL HISTOLOGY

Detailed explanation-1: -Retrosternal goiter refers to the thyroid mass grows along dermal sternum from the neck to the substernal portion, descending below the thoracic inlet. Retrosternal, substernal, or intrathoracic, goiter was first described by Haller in 1749 [1].

Detailed explanation-2: -The most common symptoms of substernal goiter result from compression of the trachea and/or esophagus and include dyspnea, choking sensation, cough, and dysphagia.

Detailed explanation-3: -A retrosternal thyroid refers to the abnormal location of all or part of the thyroid gland below the breastbone (sternum).

Detailed explanation-4: -Retrosternal goiters were graded craniocaudally as: Grade 1 (above aortic arch), grade 2 (level of aortic arch), and grade 3 (below aortic arch); and in the anteroposterior dimension as type A (prevascular), type B (retrovascular-paratracheal), and type C (retrotracheal).