What is thymoma? Is thymoma malignant Xie Dong, Department of Thoracic Surgery, Shanghai Lung Hospital, Tongji University In clinical work, patients often come to consult with the report, what is anterior mediastinal nodule? Is thymoma cancer? What are the symptoms? How to treat thymoma? Is it serious? I. Where is anterior mediastinal nodule? It is located in front of the heart, behind the sternum. 2. What are the most common diseases of the anterior mediastinal nodes? The most common diseases include: thymoma, thymic carcinoma, thymic cyst, thymic hyperplasia, and seminoma. C. What is thymoma? Thymoma is a low-grade malignant tumor that is generally slow-growing but has a risk of recurrence and metastasis. After thymectomy, it generally does not affect the immune function of adult patients. The incidence ratio between men and women is basically equal, and the high incidence age is located at 40-60 years old. Fourth, what are the symptoms of thymoma? 1). Physical examination discovery, asymptomatic The majority of patients with small nodules are asymptomatic, and the Department of Physical Examination found that there are no symptoms. 2). Symptoms of compression of peripheral tissues If the mass is large, it will produce corresponding symptoms of compression, which may include: chest tightness, chest pain (symptoms produced by direct compression of the tumor), cough, sputum (compression of lung tissue by the tumor), shortness of breath, shortness of breath (compression of lung tissue by the tumor), hoarseness (tumor encroaching on the recurrent nerve of the larynx), choking on drinking water (tumor encroaching on the supra-laryngeal nerve), swelling of the upper limbs and the head and face (compression of the innominate vein or superior vena cava by the tumor), etc., as well as non-specific symptoms. (tumor compression of the innominate vein or superior vena cava), etc., as well as non-specific symptoms, such as fever and malaise. Typical manifestations of head and face swelling After treatment, the patient’s head and neck swelling improved significantly 3). Paraneoplastic syndromes About 30% of patients with thymoma develop paraneoplastic syndromes (of which myasthenia gravis, MG, is the most common, and is most common in type B2 thymoma): (1) Neuromuscular syndromes such as myasthenia gravis. About 18% to 50% of patients with thymoma have myasthenia gravis. And about 8% to 15% of patients with myasthenia gravis have thymoma. Patients with myasthenia gravis symptoms, the main symptoms include: limb weakness, eyelid ptosis, double vision, etc. The performance is characterized by morning light and twilight heavy, that is, the early myasthenia gravis symptoms are mild, and myasthenia gravis symptoms are aggravated at night. Some patients take oral pyridostigmine bromide, rapid symptomatic improvement. (2) Aplastic anemia of simple red blood cells (severe anemia), leukopenia, thrombocytopenia and other blood disorders. (3) Immunodeficiency diseases such as hypogammaglobulinemia and T-cell deficiency syndrome, which are prone to infections. Typical diplopia Diplopia is a double vision in the eyes, either left and right, or up and down. The following figure shows the typical diplopia V. What is the typical CT presentation of thymoma? Non-invasive thymoma: round, ovoid or lobulated mass; clear border; most of the density is uniform, or cystic changes may occur; most of the tumor grows asymmetrically and resides in the anterior mediastinum; thymoma with a diameter of <2cm may only manifest as a localized elevation of the edge of the normal thymus. 2.invasive thymoma clear CT signs of invasive thymoma: encapsulation of mediastinal structures, direct invasion of central vein, pericardium or pleural implantation metastasis and late trans-diaphragmatic spread. Invasion of superior vena cava with bilateral hydrothorax 3. Thymic carcinoma Squamous carcinoma of thymus VI. Which anterior mediastinal occupations or anterior mediastinal nodules are not thymoma? 1. Doctor, is this anterior mediastinal space a thymoma? Yuanfang, this is not a thymoma, it is an ectopic mediastinal pancreas with ruptured lesion corroding the upper lobe of the left lung, causing infection of the upper lobe of the left lung. 2. Doctor, is this anterior mediastinal space, a thymoma? Answer: This is an ectopic parathyroid cyst, not a thymoma, and its location is closer to the neck. 3. Answer: This is a retrosternal thyroid gland, not a thymoma, which descends from the neck into the chest. 4. Dr. Xie, is this anterior mediastinal space a thymoma? Answer: This is a mediastinal teratoma, not a thymoma. This tumor contains a lot of fat inside, as well as calcified shadows, which are typical manifestations of mediastinal teratomas. 5. Dr. Xie, is this anterior mediastinal space, a thymoma? Answer: This is also a mediastinal teratoma, not a thymoma. This tumor has a very typical intracapsular cyst, which is also a typical manifestation of mediastinal teratoma. 6. Dr. Xie, is this mediastinal tumor a thymoma? Answer: This is a pericardial cyst, not a thymoma, but this can only be diagnosed by intraoperative exploration. 7. Dr. Xie, is this mediastinal space a thymoma? Answer: This is a bronchial cyst, not a thymoma, but sometimes mediastinal cysts include thymic cyst, bronchial cyst, pericardial cyst, which are difficult to differentiate and diagnose preoperatively, and sometimes it is difficult to diagnose even with CT combined with MRI. Thymoma is often combined with thymic cysts, so sometimes, if thymoma and mediastinal cysts are indistinguishable from each other, surgical exploration is necessary, and the final diagnosis is made by pathology. 8. Dr. Xie, is this mediastinal space a thymoma? Answer: Pathology confirms that this is not a thymoma but a lymphoid (follicular) hyperplasia of the thymus. The picture below shows another thymic hyperplasia. 9. Dr. Xie, is this mediastinal space a thymoma? Answer: Pathology confirms that this is not a thymoma but a thymic cyst. 7. Anterior mediastinal nodule, how to treat suspected thymoma In recent years, with the improvement of imaging technology, the discovery rate of anterior mediastinal nodule has significantly increased, and this part of the patient has brought great trouble to the clinical work, especially the mediastinal nodule less than 2cm, which is difficult to diagnose before operation, and the diseases that may be included include: thymoma, thymic hyperplasia, thymus, cyst, lymphoma, etc.. Thymoma, thymic hyperplasia, thymic cyst, lymphoma, etc. The lesion is located in the posterior sternum, which is difficult to perform puncture to make a clear diagnosis, and at the same time, the specificity of preoperative diagnosis is low. If the nodule is less than 1cm, regular follow-up is recommended, and direct surgery is not recommended. 2.If the nodule is larger than 2cm and thymoma cannot be excluded, minimally invasive surgery is recommended. 3.If the lesion is between 1-2cm, it is recommended to carry out magnetic resonance or PET/CT monitoring when necessary. If it suggests that mediastinal cyst is likely to be large, it can be considered to continue to follow up, and if it suggests substantial tumor, it is recommended to carry out surgical resection. Is thymoma benign or malignant, is it cancer? 1. Most thymomas are low grade malignant tumors, but a few thymomas show invasive lesions, which can invade the large blood vessels, including the innominate artery, superior vena cava, pulmonary artery, and so on, and can also show metastasis, including intrathoracic metastasis, pulmonary metastasis, pleural metastasis, supraclavicular lymph node metastasis, and even brain metastasis, bone metastasis, and so on. 2.There are also a few patients with thymic carcinoma. 3.Most patients with thymoma show low malignant tumor and inert tumor. IX. What examinations should be done before thymoma surgery 1. It is better to do thin-layer enhanced chest CT (CT with intravenous fluid) before thymoma surgery, to assess the relationship between mediastinal lesion and surrounding blood vessels or other important structures on the one hand, and the relationship between mediastinal lesion and surrounding blood vessels or other important structures on the other hand. If surgical resection is performed, is there any gap that can provide separation; on the other hand, assess whether there are metastases in the chest cavity, pleura or lungs. A considerable number of patients with thymic tumors have invasion or metastasis in the lungs or pleura, and local resection of lung tissue is required intraoperatively. If the lesion is large, or if thymic carcinoma is suspected, cranial magnetic resonance, whole-body bone scan or PET/ct should be evaluated to exclude the risk of distant metastasis. 3.Does the tumor need to be punctured before surgery? If the tumor is expected to be surgically resectable, preoperative puncture is not recommended because the lesion is located behind the sternum, which is sometimes difficult to puncture. If the tumor is not expected to be surgically resectable preoperatively, or if it cannot be differentiated from other malignant mediastinal tumors (malignant germ cell tumors, malignant lymphoma, mediastinal lung cancer), puncture can be considered to clarify the diagnosis, and then, after radiotherapy or chemotherapy, if the tumor shrinks, it can be evaluated again for the possibility of surgical resection. 4.Other tests include: lung function, electrocardiogram, arterial blood gas, electromyography, abdominal ultrasound, lower extremity venous ultrasound, neostigmine test and so on. Ten thymoma how to surgical resection For smaller size, no invasion of thymoma, generally can choose the minimally invasive treatment of thoracoscopy, this treatment is less traumatic, and fewer complications in the perioperative period, in addition, for some invasive thymoma, such as the tumor invades the pericardium or pleura, can also be treated by thoracoscopy. For some larger, invasive thymomas, such as invading large blood vessels, they need to be treated by traditional surgical resection. Minimally invasive single-port thoracoscopic surgery Yuanfang, look at the diagram below which shows the transition of thoracoscopy from four-port - three-port - two-port - all the way to single-port, with fewer incisions and more minimally invasive. Yuanfang, look, this is the patient's incision after single-port thoracoscopy, which is very small. XI. What is the prognosis for thymoma? How long can I live with thymoma? The surgical resection rate of thymoma is high. Kondo et al. reported that the resection rate of 1098 cases of thymoma at stages I, II, III and IV was 100%, 100%, 85% and 42%, respectively. And complete resection is closely related to the prognosis, Regnard et al. reported that the 10-year survival rate of 307 cases of complete resection of thymoma was 80%, 78%, 75%, and 42%, and the 15-year survival rate was 78%, 73%, 30%, and 8%, which is a good result compared with other types of malignant tumors. The prognosis of thymoma mainly depends on, thymoma typing, Masaoka staging, whether complete surgical resection, tumor size, the presence of concomitant diseases, postoperative adjuvant therapy. XII. Should thymoma be treated with chemotherapy or radiotherapy after surgery? 1. Most of the thymomas do not need chemotherapy after surgery. Stage I, stage II, type A, type AB, type B1 thymoma generally do not advocate radiotherapy after surgery, while type B2, type B3, and type C thymoma need to consider radiotherapy. 2.If the surgery is not radical and there is residual lesion, further radiotherapy is needed. 3.If pleural metastasis is inadvertently detected during surgery, radiotherapy should be performed at the tangential position of the rib-diaphragm angle on the metastatic side. 4.If it is stage IV thymoma, further chemotherapy is needed. XIII Should thymoma be treated with targeted therapy after surgery? Thymoma targeted drug research is a hotspot in recent years, and the related genes are epidermal growth factor receptor (EGFR), Kit, vascular endothelial growth factor (VEGF), Kras, human epidermal growth factor receptor 2 (HER-2), etc. Though it is actively explored, most of the results are not good. XIV Summary of thymoma To summarize, thymoma is overall a relatively benign class of low-grade malignant tumors that develop slowly but are still lethal, and early aggressive treatment is recommended. Early resection is the only effective curative measure. Chemotherapy and targeted therapy are not ideal, radiotherapy is mainly used to reduce the risk of recurrence after surgery or salvage treatment, and traditional Chinese medicine is basically ineffective. In patients with myasthenia gravis, long-term neurological follow-up is needed after surgery. Early detected thymoma can be cured by surgery alone, and the prognosis is good, so there is no need to worry too much. Early stage thymoma can be treated by single-port thoracoscopic surgery, or minimally invasive transcervical surgery, or subxiphoid thoracoscopic surgery, with a cost of about 30,000-40,000 yuan. Middle- and late-stage tumors need to be treated with open thoracic surgery; locally advanced tumors can be treated with surgical resection combined with macrovascular reconstruction. Anterior mediastinal space, besides thymoma, also includes mediastinal cyst (bronchial cyst, thymic cyst, pericardial cyst, etc.), lymphoma, mediastinal teratoma, thymic carcinoma, casttlemandisease, etc., which needs careful differential diagnosis. Anterior mediastinal nodules, in addition to thymoma, include thymic hyperplasia, thymic cysts, thymic lipoma, etc., requiring careful differential diagnosis.