Examination of intrathoracic goiter

1. In hyperthyroidism, serum T3 and T4 may increase and TSH may decrease.

2. Chest X-ray

(1) When the retrosternal goiter is small, the shadow of mediastinum does not widen, but the density of upper mediastinum increases slightly, which can often compress trachea. The existence of tumor can be inferred from the arc impression of trachea. After the tumor is enlarged, the shadow of the upper mediastinum can widen to one side or both sides. If the tumor occurs in the right lobe, the mediastinal shadow protrudes in an arc to the right or slightly to the left. If it occurs in the left lobe, the shadow only protrudes to the left when the tumor is small, and it can protrude to the right at the same time when it is large. If the tumor occurs on both sides or isthmus, the mediastinal shadow protrudes to both sides in an arc shape. Because the aortic arch is relatively fixed, it has great resistance to tumor compression, so the shadow of mediastinum mainly protrudes to the right, and the swollen thyroid gland can press the aortic arch to shift to the lower left.

(2) When the volume of goiter is large, the trachea can be compressed and displaced to the opposite side and back; Located behind the trachea, it presses the trachea to shift forward and to the opposite side; When both sides of the trachea are compressed, they are deformed like sheaths. The trachea is curved, often extending to the neck and ending at the throat. This phenomenon is strong evidence of goiter.

(3) The shadow of retrosternal goiter is connected with the soft tissue of the neck. On fluoroscopy or X-ray, we can see that the shadow of the tumor in the upper mediastinum extends to the neck. It can be differentiated from other mediastinal tumors. Because the lump is often closely connected with the trachea, it moves upward when swallowed. Without this exercise, the possibility of this disease cannot be completely ruled out.

(4) The esophagus can be displaced to the left or right due to compression, and the tumor can occasionally be embedded between the esophagus and trachea to expand the distance between them. If the esophageal mucosa is damaged, it is a malignant tumor.

(5) The edge of benign thyroid tumor may be slightly lobulated, and the edge of malignant tumor may be wavy. The density of tumor shadow is uniform, sometimes calcified, in block or point shape, and the edge is curved. However, benign and malignant tumors cannot be distinguished by calcification, and malignant tumors may metastasize to the lungs or bones.

(6) Mediastinal pneumography can clearly show thyroid tumor, and the mass can be seen in the anterior upper part of aorta in transverse section.

3.CT examination

Typical manifestations are as follows: ① It is connected with the cervical thyroid gland, located in pretracheal space, and can also extend to the back of trachea and esophagus; ② Clear boundary; ③ Punctate and annular calcification; ④ Most tumors are solid shadows with uneven density, accompanied by low density areas with or without enhancement; ⑤ With tracheal displacement, compression, esophageal compression, etc. ⑥CT value is higher than that of surrounding muscle tissue. Generally, it is 50 ~ 70 Hu, sometimes it can reach 1 10 ~ 300 Hu, and the CT value of cystic area is 15 ~ 35 Hu.

4.b ultrasound, MRI and DSA

B-ultrasound can determine whether the mass is cystic or solid. MRI can understand the relationship between the mass and the surrounding great vessels, and exclude the possibility of hemangioma. DSA can understand the source of blood supply of tumor and the blood circulation of tumor itself.

5. Radionuclides

Examination of 13 1I can determine whether the mass is thyroid tissue, its size, location or whether there are hot nodules secondary to hyperthyroidism.