What is lymphoma?
Lymphoma is a malignant tumor that originates in the lymph nodes or lymphatic tissue. The main clinical manifestation is painless, progressive lymph node enlargement. The disease can occur at any age, but the peak age of onset is 31-40 years, with a slightly more advanced peak for non-Hodgkin’s lymphoma. The ratio of men to women is 2-3:1.
What causes lymphoma?
The cause of human lymphoma is not known. Only two viruses are clearly associated with lymphoma in humans, EBV and human T-cell lymphoma/leukemia virus. They are classified into Hodgkin’s disease and non-Hodgkin’s lymphoma based on their pathological characteristics.
What are the symptoms of lymphoma?
1. Lymph node and lymphatic tissue onset.
Superficial lymph nodes account for most of the disease, and HD is more common than NHL. the most affected lymph nodes are in the neck, followed by the axillae and groin. They are usually painless, progressively enlarged, and moderately hard. In the early stage, the lymph nodes are mobile, but in the late stage, adhesions and fusion of multiple enlarged lymph nodes into a mass are common. In some HD patients, the enlargement of lymph nodes may temporarily stop or even shrink at some time, leading to misdiagnosis of lymphadenitis or lymphatic tuberculosis.
The deep lymph nodes, most commonly the mediastinal lymph nodes, may compress the superior vena cava and cause superior vena cava syndrome. The enlarged lymph nodes may compress the superior vena cava and cause superior vena cava syndrome. They may also compress the trachea, esophagus, and laryngeal nerve and cause dyspnea, dysphagia and hoarseness. Mediastinal NHL is more commonly associated with lymphosarcoma cell leukemia. The first mediastinal HD in young women is mostly of the nodular sclerosis type and often responds unsatisfactorily to treatment.
Malignant lymphomas originating in retroperitoneal lymph nodes, most commonly NHL, can cause prolonged, unexplained fever, making clinical diagnosis difficult. Lymphomas that first arise in the pharyngeal lymphatic ring are most often seen in NHL and are often accompanied by subphrenic invasion. Symptoms include sore throat, foreign body sensation, dyspnea and hoarseness.
2. Extra-nodal origin.
It can develop in any part of the body except lymphatic tissues, among which primary lymphoma in the stomach and high small intestine is the most common. Lymphoma in the stomach and high small intestine can have symptoms such as epigastric pain and vomiting. Small intestinal lymphoma is usually found in the ileocecal region, and often has chronic diarrhea, but also can occur in steatorrhea, and can also cause intestinal obstruction.
3.Systemic symptoms.
There are often general weakness, emaciation, loss of appetite, night sweats and irregular fever. A small number of HD may have periodic fever.
What tests should be done for lymphoma?
1.Blood picture.
Early stage is usually not special. Anemia is seen in advanced stage or combined with hemolytic anemia. Leukocytes are generally normal except for bone marrow involvement, and eosinophilia, common in HD. Lymphocytes are reduced in absolute value in about 1/3 of HD patients. Plasma cells and Reed-sternberg cells are occasionally seen in peripheral blood. Decreased platelets suggest bone marrow involvement or secondary to hypersplenism.
2. Bone marrow picture.
Bone marrow is usually abnormal before lymphoma invasion. Bone marrow smear of HD with Reed-sternberg cells is valuable for diagnosis. These cells are large in size, 15-20μ in diameter, with large nuclei, which may be lobulated, binucleated (microscopic cells) or multinucleated. The chromatin is unevenly distributed and densely packed. The nuclear membrane is thick and deeply stained. The nucleolus is large and garden, up to 8μ, with hollow halo area around the nucleolus.
3.Biochemical examination.
Elevated lactate dehydrogenase reflects the rapid proliferation of tumor cells, and >500 units/L indicates poor prognosis of NHL. Serum copper and ferritin increase during disease progression and decrease during remission; zinc is the opposite. Elevated alkaline phosphatase may have liver or bone involvement. Liver involvement may be accompanied by elevated 5-nucleotidase. Hypercalcemia is suggestive of bone invasion, and such changes may precede radiographic changes. Elevated cerebrospinal fluid β2 microglobulin suggests central nervous system involvement.
4. Immunological abnormalities.
HD patients have reduced responsiveness to tuberculin and other stimulants and reduced in vitro lymphocyte conversion, the extent of which is related to disease progression. Humoral immunity is generally normal, immunoglobulins are usually normal or increased, and may decrease in advanced stages. some patients with NHL have humoral immune abnormalities, manifested as autoimmune hemolytic anemia, immune thrombocytopenia, etc. Coombs test is positive, and a few patients have monoclonal hyperglobulinemia. In patients who achieve remission with treatment, immune function may return to normal.
The diagnosis of lymphoma is described as follows.
1. Biopsy.
It is an indispensable examination method for affirmative diagnosis. Lymph nodes in the lower neck or axilla should generally be selected, because lymph nodes in the submandibular and inguinal areas often have chronic inflammation, which affects the accuracy of diagnosis. Oblique muscle fat pad biopsy has some diagnostic significance for mediastinal or pulmonary lesions.
2.Mediastinoscopy.
Mediastinoscopy can enter the mediastinum for biopsy via extrapleural, which is relatively easy and safe.
3.Lymphangiography of lower limbs.
It is a more accurate, safe, simple and less complicated examination technique for diagnosis, staging, judging the efficacy and observing recurrence of retroperitoneal lymphoma, and it is superior to CT and sonogram in some aspects, and it can find the internal structural changes of diseased lymph nodes of normal size.
4. CT, MRI and sonography.
It can detect intra-thoracic, retroperitoneal, mesenteric lymph node lesions and liver and spleen lesions.
5.Dissection examination.
It can clarify whether the spleen, liver and intra-abdominal lymph nodes are involved, which is essential to determine the irradiation field (pathological staging) for the use of radiation therapy. If splenectomy is done at the same time, it can also avoid damage to adjacent tissues and organs due to radiotherapy in the splenic area.
6.Bone marrow biopsy.
It has a higher positive rate than bone marrow smear for diagnosis and identification of the stage of disease. All patients with elevated serum alkaline phosphatase, unexplained anemia, thrombocytopenia, suspected bone invasion on X-ray and stage III or above should undergo bone marrow biopsy.
7. Differential diagnosis.
Clinically, malignant lymphoma is easily misdiagnosed. For superficial lymph node enlargement, it should be differentiated from chronic lymphadenitis, lymph node tuberculosis, metastasis, lymphocytic leukemia, immunoblast lymphadenopathy, eosinophilic lymphocytic granuloma, etc. In cases with deep mediastinal lymph nodes, the disease should be differentiated from lung cancer, nodal disease, and giant lymph node hyperplasia. If fever is the main manifestation, it should be distinguished from tuberculosis, malignant histiocytosis, septicemia, rheumatic fever, connective tissue disease, etc.
How to treat?
1.Radiotherapy.
(1) Sub-total lymphatic field irradiation can be used for HD ⅠA and ⅡA alone.
(2) NHL low grade ⅠA and ⅡA should be treated with radiotherapy followed by chemotherapy.
2.Chemotherapy.
(1) HD stage IIIB-V cases should be treated with chemotherapy, combined with chemotherapy regimen MOPP for 6 courses, the complete remission rate can reach 60-80%, with 1/2-1/3 cases maintaining long-term remission, some up to 15 years.
(2) Low and moderate stages III and VI of NHL and highly malignant stage I-IV cases are suitable for chemotherapy, and then regional radiotherapy as appropriate after the tumor has achieved remission.
3.Surgical treatment.
Surgical radical treatment followed by radiotherapy and chemotherapy is feasible for those with the following conditions.
(1) H limited extra-nodal lesions on the body surface.
(2) H gastrointestinal lymphoma.
(3) H genitourinary lymphoma.
(4) H primary lymphoma of the spleen.
4. Bone marrow transplantation.
Autologous transplantation has positive efficacy in lymphoma. Allogeneic transplantation is suitable for young patients with high malignancy and poor results of common treatment methods (including radiation, chemotherapy and autologous transplantation).