Pulmonary lymphoma is a malignant lymphoproliferative tumor of extranodal localization originating from lymphoid formations of the bronchopulmonary system. Disease clinic consists of nonspecific symptoms (blurred weakness, periodic subfebrility) and signs of respiratory tract damage (unproductive cough, shortness of breath, chest pain, etc.). The diagnosis is made on the basis of radiological data (radiography, CT, MSCT of the lungs), confirmed by the examination of biopsy material. The choice of tactics for the treatment (surgery, radiation therapy, polychemotherapy) is carried out taking into account the degree of malignancy and prevalence of the lesion.
ICD 10
C85 Other and unspecified types of non-Hodgkin’s lymphoma
Meaning
Pulmonary lymphoma is a tumor lesion of the lymphoid apparatus of the lower respiratory tract. It can occur in the form of Hodgkin’s disease and malignant non-Hodgkin’s lymphomas. Pathology occupy a leading place in the structure of extranodal lesions (i.e. lesions of organs not related to the lymphatic system). In lymphoproliferative diseases, the interest of the lung tissue is detected in 0.5-40% of cases. Pulmonary lymphomas are an urgent interdisciplinary problem combining knowledge and efforts in the field of pulmonology, hematology and oncology.
In Hodgkin’s disease, lung damage usually serves as a local manifestation of a systemic process; an independent local form of lymphogranulomatosis of the lung is much less often diagnosed. In most cases, isolated primary pulmonary lymphomas belong to B-cell non-Hodgkin’s lymphomas – the so-called MALT lymphomas originating from lymphoid formations of the mucous membrane. Secondary pulmonary lymphomas are metastatic formations that spread directly or hematogenically from other foci.
Causes of pulmonary lymphoma
Pulmonary lymphoma has common etiological roots with other lymphoid tumors, however, to date, knowledge about their causes cannot be considered exhaustive. In recent years, data on the viral origin of some malignant lymphomas have been obtained. At the same time, there was a more frequent association of lymphoid tumors with Epstein-Barr viruses, herpes type 8, hepatitis C, human T-lymphotropic virus, HIV.
Other possible risk factors include contact with chemical carcinogens (fertilizers, insecticides, herbicides, solvents, etc.), autoimmune diseases, long-term immunosuppressive therapy. The latter circumstance determines the fact that malignant lymphomas occur somewhat more often in people who have undergone organ or bone marrow transplantation. Often, various structural chromosomal abnormalities are detected in patients with lymphoma. Contrary to popular belief, smoking does not affect the incidence of pulmonary lymphoma.
Classification
Among malignant pulmonary lymphomas there are:
1. Primary non-Hodgkin’s lymphomas (lymphosarcomas):
- B-cell (MALT-lymphoma, mantle lymphoma, etc.)
- T-cell
2. Lymphogranulomatosis (Hodgkin’s disease).
3. Plasmocytoma.
4. Secondary lymphoproliferative lung lesions in malignant lymphomas of other localizations.
MALT lymphoma is the most common variant of extranodal lymphoma. MALT lymphoma of the lungs may have a limited localization for many years; bone marrow damage is observed in no more than 5% of cases. It usually develops against the background of chronic bronchopulmonary infections and autoimmune diseases (systemic lupus erythematosus, multiple sclerosis, Sjogren’s disease, etc.). In some cases, MALT lymphoma of the lungs with a low degree of malignancy can transform into a tumor with a high degree of aggressiveness (the causes and probability of such a transformation are unknown).
Pulmonary lymphogranulomatosis can occur in the following clinical and morphological forms:
- nodular – with the formation of single or multiple nodes in the lungs (more often in the lower lobe) (up to 3-5 pieces). In the case of bronchial compression, a clinic of purulent bronchitis or abscessing pneumonia develops.
- peribronchial – with the formation of strands stretching along the course of the bronchi. If granulomatous growths spread to the alveolar septa, interstitial pneumonia occurs, which can capture from one lobe to the whole lung.
- exudative – with the development of granulomatous lobular or lobular pneumonia.
- miliary (submiliary) – with a disseminated scattering of millet-shaped granulomatous nodules on the lung tissue.
Symptoms of pulmonary lymphoma
Primary lymphomas of the lung have a latent course for a long time. They equally often affect men and women and are usually detected in the older age group (50-60 years). The asymptomatic period can vary from several months to several years, so lymphomas are often accidentally detected during a routine X-ray examination. Most often, lymphoma affects the bronchi or parenchyma of the lung, while in 60-70% of cases, bilateral localization of the tumor is detected.
Clinical symptoms usually develop against the background of bronchial obstruction or partial lung atelectasis, accompanied by cough, chest pain, hemoptysis, recurrent bronchopulmonary infections. Systemic signs of intoxication (mild weakness, sweating, subfebrile temperature) at first are often perceived as signs of ARVI. In progressive stages, pulmonary lymphoma can cause metastatic damage to the mediastinum, gastrointestinal organs, thyroid gland, mammary glands, testicles, bone marrow.
With lymphogranulomatosis, there is an increase and soreness of the lymph nodes (more often cervical, supraclavicular, axillary), unproductive cough, chest pain, shortness of breath. When the pleura is interested, pleurisy often develops.
Plasmocytic malignant lymphoma of the lungs (plasmocytoma) is rare, mainly in men. Usually it is a solitary node located against the background of unchanged lung tissue. Local plasmocytomas can exist for a long time, occasionally causing meager clinical symptoms: cough, chest pain, fever. With the removal of the primary node, a cure may occur; with the generalization of the process, a transition to multiple myeloma (myeloma) occurs.
Diagnostics
The main methods of diagnosing pulmonary lymphoma are traditional radiation examinations. First of all, the patient is chest x-ray in 2 projections. If characteristic changes are detected on radiographs (focal shadows, diffuse tumor infiltration, lymphangitis, pleural effusion, etc.), MSCT or CT of the lungs is also performed for a more detailed assessment of changes and staging of the tumor process.
According to modern requirements, radiological data indicating pulmonary lymphoma must be confirmed histologically. To verify changes in the lung tissue, a transbronchial (during bronchoscopy) or transthoracic lung biopsy is performed with further cytological and immunohistochemical examination of the biopsy. In some cases, in order to obtain the necessary material, it is advisable to resort to a lymph node biopsy, diagnostic thoracoscopy or exploratory thoracotomy. Pulmonary lymphoma has to be differentiated with bronchoalveolar cancer, carcinomatous lymphangitis, histiocytosis X of the lungs, tuberculosis, sarcoidosis, benign lymphoid hyperplasia, etc.
Treatment for pulmonary lymphoma
Treatment of isolated pulmonary lymphoma at the local stage is usually surgical (lobectomy, pneumonectomy), supplemented by radiation therapy. With bilateral, generalized lesions, multiple foci, high malignancy of lymphoma and other aggravating factors, polychemotherapy or combined treatment (radiation therapy + chemotherapy, polychemotherapy in combination with monoclonal antibodies to B lymphocytes (rituximab) is indicated.
The survival rate over the next 5 years for primary MALT lymphomas of the lungs is more than 60%, which is regarded as a good prognosis. With T-cell non-Hodgkin’s lymphomas, lymphomas with a high degree of malignancy, generalized lesion, metastatic process in the lungs, survival is low, the prognosis is doubtful.
