Mediastinal lymphoma is a malignant type of tumor that develops from mediastinal lymph nodes. In most cases, mediastinal lymphoma is manifested by symptoms of compression of the chest cavity: cough, difficulty breathing and swallowing, chest pain; itching, night sweats are often noted. Mediastinal lymphoma is detected by radiography and CT, the diagnosis is confirmed after mediastinoscopy, histological and immunomorphological examination of the tumor fragment. Standard lymphoma treatment regimens include radiation and chemotherapy; in some cases, surgical removal of a mediastinal tumor is possible.
C85 Other and unspecified types of non-Hodgkin’s lymphoma
The term “mediastinal lymphoma” refers to non-Hodgkin’s (reticulosarcoma, lymphosarcoma) and Hodgkin’s (lymphogranulomatosis) lymphomas that primarily affect the lymph nodes of the mediastinum. Among all mediastinal tumors, lymphomas make up a small group, however, the frequency of mediastinal lesions in lymphogranulomatosis is up to 90%, and in non-Hodgkin’s lymphomas – up to 50%. Mediastinal lymphomas are mainly found in young and middle-aged people (20-45 years old).
Most often, lymphomas are localized in the anterior-upper floor of the mediastinum. Prolonged indolent (with lymphogranulomatosis) or rapid aggressive (with lymphosarcoma) course complicate the timely detection of malignant lymphomas. Solving this problem requires the integration of the efforts of specialists in the field of oncology and thoracic surgery.
Causes of mediastinal lymphoma
In most cases, the immediate cause of mediastinal lymphoma in a particular patient remains unclear. However, hematology is aware of factors that increase the likelihood of lymphoid neoplasia in the general population. The high-risk group includes patients:
- who have had infectious mononucleosis, viral hepatitis C
- people suffering from autoimmune pathology (SLE, rheumatoid arthritis, etc.)
- those whose closest relatives suffered from hemoblastosis
- having genetic pathologies characterized by primary immunodeficiency are the Viscott-Aldrich, Louis-Bar syndromes (with-m ataxia–telangiectasia), Duncan, etc.
- persons undergoing chemotherapy or radiation treatment for other oncological
- diseases receiving immunosuppressive therapy after organ transplantation.
Among the unfavorable exogenous factors, primary importance is attached to industrial hazards, environmental problems, excessive insolation, increased consumption of animal proteins. The effect of alcohol and tobacco use on the development of lymphomas has not been unequivocally confirmed.
Mediastinal lymphomas may have a primary (initially develop in the mediastinal space) or secondary origin (they are metastatic neoplasms or a manifestation of a generalized form of lymphogranulomatosis).
Symptoms of mediastinal lymphoma
Mediastinal lymphogranulomatosis in the initial stages proceeds with minimal symptoms. Often, an increase in mediastinal nodes detected by chest X-ray is the only sign of the disease. Initial clinical manifestations usually include malaise, increased fatigue, insomnia, decreased appetite, weight loss. Periodic rises in body temperature, dry cough, sweating at night, skin itching are characteristic.
In the late stages of Hodgkin’s lymphoma of the mediastinum, a compression syndrome develops caused by compression of mediastinal structures. The clinical expression of this syndrome can be shortness of breath, tachycardia, swallowing disorders, hoarseness of voice, puffiness of the neck and face (superior vena cava syndrome). During examination, an increase in cervical and axillary lymph nodes, chest bulging, and expansion of subcutaneous veins on the chest are often determined.
They are more often represented by reticulosarcoma, nodular or diffuse mediastinal lymphosarcoma. They are characterized by rapid infiltrative growth and early metastasis to the lungs, bone marrow, spleen, liver, and skin. With mediastinal lymphosarcoma, signs of compression mediastinal syndrome prevail – difficulty breathing, choking cough, dysphonia, cyanosis, compression of ERW.
Approximately 10% of patients with mediastinal lymphoma have exudative pleurisy or chylothorax caused by obstruction of venous or lymphatic outflow or tumor invasion of the pleura. In advanced stages, the tumor can germinate the pericardium, aorta, diaphragm, chest wall.
Lymphomas of mediastinal localization are not always diagnosed during X-ray examination. Computed tomography, in more detail than survey radiography, allows us to consider the tumor conglomerate, enlargement of mediastinal lymph nodes, involvement of paratracheal, tracheobronchial, basal lymph nodes. The diagnostic significance of magnetic resonance imaging in the verification of mediastinal lymphomas is not recognized by all authors.
In addition to these studies, mediastinal ultrasound is used to assess the condition of intra-thoracic lymph nodes that are inaccessible for X-ray imaging. An even more highly sensitive method is lymphoscintigraphy with gallium citrate. Bronchoscopy is performed to detect compression of the trachea and bronchi.
Since the tactics of treatment of mediastinal lymphoma is determined by the histological and immunohistochemical type of tumor, a biopsy is an obligatory stage of diagnosis. With an increase in the lymph nodes available for palpation, excision, puncture or pre-calcified biopsy is performed. In other cases, surgical biopsy is resorted to using mediastinoscopy, parasternal mediastinotomy, diagnostic thoracoscopy.
It is necessary to differentiate mediastinal lymphoma with other mediastinal tumors, mediastinal cyst, sarcoidosis, HCV tuberculosis, echinococcosis, lymphadenitis of various etiologies, lung cancer metastases, mediastinitis, etc.
Treatment for mediastinal lymphoma
The choice of treatment protocol for mediastinal lymphoma depends mainly on the type and prevalence of the tumor. With local lymphogranulomatosis, local radiation therapy is indicated. Sometimes, with an isolated lesion of mediastinal lymph nodes, they resort to their surgical removal followed by radiation treatment. The algorithm for the treatment of common stages of lymphogranulomatosis provides for combined chemoradiotherapy or polychemotherapy.
Mediastinal lymphosarcomas also respond well to treatment using conservative methods – radiation and chemotherapy. Many oncologists and thoracic surgeons in recent years have spoken out for the validity of surgical removal of mediastinal lymphoma. In operable cases, the operation can be performed already at the diagnostic stage (the so-called total biopsy), but most surgeons recognize the expediency of performing it after preliminary antitumor therapy (removal of a residual tumor).
The success of treatment and survival of patients with mediastinal lymphoma largely depends on the immunomorphological diagnosis. The 5-year relapse-free survival threshold for local forms of Hodgkin’s lymphoma is overcome by 90% of patients; with stage IV lymphogranulomatosis, even after polychemoradiotherapy, this indicator is no more than 45%. Lymphosarcomas have a much more unfavorable prognosis due to the rapid generalization of the process and frequent recurrence.
- Mediastinal lymphomas: histopathology. Chetaille B. Rev Pneumol Clin. 2010 Feb;66(1):28-31.link
- Clinicopathologic study of 40 cases of mediastinal tumours of haematopoietic and lymphoid tissues. Chen DB, Wang Y, Song QJ, Shen DH. Zhonghua Bing Li Xue Za Zhi. 2012 Jun;41(6):376-81. link
- Mediastinal large B-cell lymphoma. Artemieva AS, Semiglazova TY, Frank GA. Vopr Onkol. 2015;61(2):280-8. link
- Primary Mediastinal Nodal and Extranodal Non-Hodgkin Lymphomas: Current Concepts, Historical Evolution, and Useful Diagnostic Approach: Part 1. Piña-Oviedo S, Moran CA. Adv Anat Pathol. 2019 Nov;26(6):346-370. link