Secondary retrosternal goitre derives its blood supply from :: (A) Mediastinal vessels, (B) Thyroid vessels, (C) Arch of aorta, (D) Bronchial vessels
Answer is B. Secondary retrrosternal goitre : Is the extension of thyroid tissue to mediastinum from thyroid in the neck. and it derives blood supply from thyroid vessels.
Primary retrrosternal goitre : Is the ectopic thyroid tissue in the mediastinum and it derives blood supply from mediastinal vessels.