Thyroid lymphoma is a non–epithelial malignant tumor of the thyroid gland that develops from lymphoid tissue. With pathology, there is an increase in the neck and cervical lymph nodes, symptoms of compression of surrounding organs develop (dysphagia, hoarseness of voice, shortness of breath). Disease is diagnosed on the basis of ultrasound, CT of the neck, fine needle biopsy with cytological and immunohistochemical examination of the biopsy. The standard practice for the treatment of lymphoid neoplasia is chemotherapy or combined chemoradiotherapy; in localized forms of thyroid lymphoma, a thyroidectomy with lymphodissection is performed.
Meaning
Thyroid lymphoma is a malignant lymphoproliferative tumor of the thyroid gland. In endocrinology, primary lymphoma is distinguished, occurring in 2-8% of all independent thyroid tumors, and secondary gland damage in other lymphoid neoplasias (lymphomas, leukemias, etc.), accounting for up to 10% of cases. Lymphoma usually develops in people older than 60-70 years, in women 3 times more often than in men.
Causes
Currently, it has been proven that most cases occur against the background of lymphoid tissue hyperplasia in autoimmune thyroiditis. This is confirmed by the fact that 83% of patients with lymphoma have a history of Hashimoto’s thyroiditis, confirmed histologically and immunologically. It is believed that as a result of prolonged antigenic stimulation of thyrocytes in autoimmune thyroiditis, lymphocytes transform, which ultimately leads to the development of thyroid lymphoma.
Among other risk factors and lymphomas of other localizations, the influence of ionizing radiation, chemical carcinogens, viruses, and environmental conditions is traditionally called. Lymphoma has a rapid diffuse growth, forms large nodes that increase the volume of the thyroid gland by 2-4 times and occupy the entire gland or a significant part of it. Usually, the lymph nodes of the neck are involved in the process. With this disease, hypothyroidism usually develops.
Stages
Classification of the stages of thyroid lymphoma is carried out according to the Ann Arbor system, in which the letter “E” is additionally placed after the Roman numeral indicating the stage of the disease to identify extranodal lymphomas.
- IE – primary lymphoma is limited to the thyroid gland
- IIE – the spread of lymphoma is limited to the thyroid gland and regional lymph nodes of the neck.
- IIIE – the germination of lymphoma into nearby organs, the defeat of lymph nodes above and below the diaphragm
- IV – involvement of distant organs and systems in the process, including the gastrointestinal tract, lungs, bone marrow, spleen, liver.
Depending on the manifestations, there are sub-stages in each stage:
- A – there is no loss of body weight, fever, intoxication
- B – there is a loss of body weight, fever, intoxication
Symptoms
Thyroid lymphoma develops in a short time, progresses rapidly and increases in size. In most cases, patients pay attention to the change in the configuration of the neck and independently detect the tumor. Most often, lymphoma occupies one lobe of the thyroid gland or a lobe and an isthmus, and there is also a unilateral increase in regional lymph nodes. During palpation, attention is drawn to the woody density of the tumor and its non-displacement relative to the trachea.
Infiltrating growth of thyroid lymphoma leads to compression and germination of surrounding tissues and organs already in the early stages of the disease. Compression and invasion of adjacent anatomical structures of the neck is accompanied by dysphagia, laryngeal paresis or paralysis of the vocal folds, dysphonia, dyspnea, displacement of the esophagus and trachea.
With lymphoma, the function of the thyroid gland is usually reduced, but the clinic of hypothyroidism develops only in half of cases. Already at the early stages of the development of thyroid lymphoma, symptoms of intoxication, fever, torrential night sweats, increasing weakness, cachexia are expressed.
Diagnostics
At the initial examination of the endocrinologist, in half of the cases, a visible increase in the thyroid gland and cervical lymph nodes is determined. In the anamnesis, attention is drawn to the rapid increase in thyroid tumors, symptoms of compression of surrounding organs. The diagnosis is confirmed by conducting a fine needle aspiration biopsy with cytological and immunohistochemical examination of the biopsy.
Clarifying diagnostic methods include a biochemical blood test with mandatory determination of the concentration of lactic acid dehydrogenase and uric acid; a general blood test, a study of thyroid hormone titers. Imaging studies include thyroid ultrasound, CT of the neck, chest X-ray, ultrasound of the abdominal cavity and pelvis. To exclude the metastasis of thyroid lymphoma to the bone marrow, bone marrow aspiration and trepanobiopsy are performed.
Differential diagnosis of lymphoma is carried out with sarcoma, thyroid cancer, thyroid nodules, autoimmune thyroiditis.
Treatment
The tactics of managing patients is determined by the prevalence of the existing process and its morphological variant. With a localized type of thyroid lymphoma, a thyroidectomy with lymphodissection is performed, which in the postoperative period is supplemented with radiation therapy or polychemotherapy (vincristine, doxorubicin, cyclophosphane), followed by immune correction and HRT of postoperative hypothyroidism and hypoparathyroidism.
With an extrathyroid (common) variant of disease, chemotherapy or combined chemoradiotherapy is prescribed. Combined treatment makes it possible to achieve an increase in the relapse-free 5-year survival rate up to 90%, therefore, this scheme is accepted as the standard treatment for thyroid lymphoma.