Diagnostic examination of mediastinal teratoma

Most teratomas are located in the anterior mediastinum, and more are located in the middle of the anterior mediastinum, at the junction of the heart and the aortic arch. A few higher masses have their upper edge crossing the top of the aortic arch, or they may be located lower in the lower part of the anterior mediastinum. Occasionally, they may be located in the posterior mediastinum. X-ray and CT examinations show dense round, quasi-round or nodular masses at the level of the heart base in the anterior mediastinum. If bones or teeth are seen, it has diagnostic significance. When the tumor penetrates into the lungs or bronchus, the patient coughs up sebaceous gland secretions or hair, which has characteristic diagnostic value.

Laboratory examination: benign teratomas are negative for tumor markers, but teratomas with malignant tissue components, especially those containing embryonic components, may be positive for tumor markers, such as AFP, HCG, LDH, or CA19-9, and the titers of the above indicators decrease after tumor resection. If there are leiomyosarcoma components, myosin detection may be positive, tumors containing neural components are positive for S-100 protein, and positive keratin staining indicates that the tumor cells contain adenocarcinoma and squamous cell carcinoma components.

Other auxiliary examinations:

1. It can be found by routine X-ray examination. Generally, it only protrudes to one side of the mediastinum, and in some cases it can protrude to both sides. Sometimes the size of the tumor varies greatly, and a large tumor can even fill one side of the chest cavity. Teratomas are usually round, oval, and multicystic ones are lobed. The outline of the tumor is clear and smooth. Some dermoid cysts have inflammatory adhesions and pleural thickening around them due to secondary infection, making the outline slightly irregular. Because teratomas contain a variety of different tissue structures, they show uneven density. The areas with more fat tissue have low density, and the cyst wall can be calcified. The shadows of bones and teeth can be seen in the tumor, which is a characteristic manifestation of this type of tumor. If the tumor increases significantly in a short period of time, it should be considered malignant, and malignant tumors are more likely to be solid tumors.

2. The characteristic manifestation of CT scan is that the mass with fat density as the main component contains calcified solid nodules, or the mass is combined with liquid part. The fat part is at the top, and the liquid part is at the bottom. There is a fat-liquid surface between the two. At this interface, a linear or cord-like circular shadow of mixed density can be seen, which is a hair mass. When the tumor has secondary infection, there are inflammatory adhesions and pleural thickening around it, and its outline is blurred. CT scan can roughly determine the size of the tumor and its relationship with the surrounding tissues. If it is suspected that the lesion has metastasized, abdominal CT, brain CT and bone scan can provide corresponding evidence.