What Is Thymoma?

The thymus is an important immune organ of the human body. It originates from the 3rd (or 4th) gill arch endoderm in the embryonic period and is a derivative of primitive foregut epithelial cells that attaches to the anterior mediastinum as the embryo grows and develops. Thymic tumors that originate from thymic epithelial cells or lymphocytes are the most common, accounting for 95% of thymic tumors.

Basic Information

English name

thymoma

Visiting department

Thoracic Surgery

Common causes

unknown

Common symptoms

The tumor has grown to a certain size, and chest pain, tightness, cough, and anterior chest discomfort

Contagious

no

Clinical manifestations of thymoma

The clinical symptoms of thymoma arise from the compression of the surrounding organs and the symptoms unique to the tumor itselfcomplication syndrome. Small thymoma is often asymptomatic and difficult to detect. When the tumor grows to a certain volume, the common symptoms are chest pain, tightness, cough, and anterior chest discomfort. Symptoms are prolonged, and some patients have X-ray examinations or some patients find shadows of mediastinal tumors during chest radiographs or chest radiographs. The neglected thymoma often grows to a relatively large volume at this time, compressing the innominate vein or showing signs of superior vena cava obstruction syndrome. Severe chest pain, rapid exacerbation of symptoms in the short term, severe irritating cough, dyspnea caused by pleural effusion, palpitation and shortness of breath caused by pericardial effusion, and pain in joints and bones all indicate the possibility of malignant thymoma.

The characteristic manifestations of thymoma are combined with certain syndromes, such as myasthenia gravis, simple red cell aplastic anemia, hypoglobulinemia, nephrotic nephrotic syndrome, rheumatoid arthritis, lupus erythematosus, and megaesophageal disease.

Thymoma examination

1. X-ray inspection

It can display the mediastinal widening, anterior mediastinal mass image, and understand whether the heart shadow is enlarged and the lung tissue is infiltrated.

2. Chest CT or MRI

It is helpful to understand the scope, size and pericardial situation of tumor invasion, so as to facilitate staging and development of treatment plan.

3. Pathological biopsy

The histological classification of biopsy before treatment is necessary because there are many types of mediastinal tumors. The simple method is to perform histological classification with acupuncture or special empty needle puncture. The necessary thoracotomy and frozen histological examination were performed to determine whether surgery could be performed.

Thymoma diagnosis

X-ray examination is an important method to find and diagnose mediastinal tumors. The chest radiograph is in a positive phase. Thymoma often appears as a round or oval dense shadow that widens on one side or protrudes to one side of the thorax. It protrudes more to the right than to the left.

Chest CT is an advanced and sensitive method for examining mediastinal tumors. It can accurately display the location, size, protrusion of one or both sides of the tumor, the edge of the tumor, the presence of peripheral invasion, and the judgment of surgical resection.

Differential diagnosis of thymoma

Lesions that need to be distinguished from thymoma include teratoma and ascending aortic aneurysm. Teratomas often occur in young and middle-aged people. They can be asymptomatic, or have recurrent lung infections, and sometimes have a history of coughing hair or oily substances. X-ray examination may show teeth or bone calcification in the mass. Cystic malformations Fetal tumors were identified by ultrasound.

Mediastinal tumors are mistaken for ascending aortic aneurysms, or they are misdiagnosed as thymomas. Ascending aortic aneurysms on the chest side are fusiform, circular shadows, along the left ventricle, thoracic masses show dilated pulsations, auscultation can be heard and murmurs, two-dimensional ultrasound examination can find ascending aorta dilatation, color Doppler The turbulence spectrum can be seen on Leak examination, and the chest CT image can show the localized tumor-like expansion of the ascending aorta. Ascending aortic angiography is available when diagnosis is difficult.

In recent years, the clinical application of MRI has gradually increased. It has special value for the diagnosis of cardiac macrovascular malformations and hemangiomas. It is a sensitive and effective test method to distinguish mediastinal tumors from ascending (descending) aortic aneurysms.

Thymoma complications

Myasthenia gravis

It has long been known that myasthenia gravis is associated with the thymus (or thymoma). Myasthenia gravis can be divided into 3 types clinically, such as drooping eyelids, long-term fatigue of eyesight, and diplopia, which are eye muscle types; upper limb extension cannot be sustained, and you need to sit down and rest as a trunk type; walking and swallowing are laborious, and even Respiratory muscle paralysis is of the bulbar type. Clinically the most dangerous is the myasthenia crisis, the patient's respiratory muscle paralysis must be artificially assisted breathing.

At present, myasthenia gravis is an autoimmune disease, which is mainly caused by a mutation in the thymus caused by a certain type of stimulation. For many years, anti-acetylcholinesterase drugs have been used to treat myasthenia gravis, such as pyridosmine. , Such as hormones, cyclophosphamide and so on.

2. Simple red cell aplastic anemia

One of the diseases coexisting with thymoma is simple red blood cell aplastic anemia. Pure red aplastic anemia can be primary, for unknown reasons, or secondary to drugs, infections, and tumors.

3. Nephrotic syndrome nephritis

The relationship between nephritis nephritis and thymoma is unknown. Nephrotic syndrome can be part of the systemic manifestations of certain tumors, such as Hodgkin's disease. A possible explanation is that thymoma cross-reacts with the antigen-antibody complex of glomerulonephritis.

Thymoma treatment

Treatment principle

Once a thymoma is diagnosed, it should be surgically removed. Both benign and malignant thymoma should be removed as soon as possible. Resected malignant thymoma can be treated with pathological biopsy to guide postoperative treatment. Partial resection can relieve symptoms and prolong the survival time of patients.

2. Problems to be aware of during surgery

Isolated benign non-adhesive thymoma, complete removal without difficulty, surgery can be successfully completed, but in some complicated cases, the difficulty should be fully estimated during surgery. Malignant thymoma must be explored first, and the relationship between the tumor and surrounding organs must be clarified before dissection. Thymoma is located at the bottom of the mediastinal heart, at the junction of the heart and large blood vessels; malignant thymoma infiltrates the surrounding adhesions; when the tumor grows, adjacent tissues and organs are shifted, and the normal anatomical relationship changes; the fibrous connective tissue adhesions thicken, making it difficult to distinguish from the blood vessels, These can cause accidental injury of blood vessels during surgery and cause major bleeding.

Thymoma prevention

There is no effective preventive measure for this disease. Early diagnosis and early treatment are the key to the prevention and treatment of this disease. At the same time, care should be taken to prevent the occurrence of various complications. Once they occur, they should be actively treated to prevent further development of the disease.