Plasmocytoma is a malignant tumor of plasma cells that affects bones and internal organs. The disease can occur in a solitary form in the presence of only one pathological focus or in a generalized version, when different body systems are involved in the process. Plasmocytoma is characterized by a variety and non-specificity of clinical symptoms, which depends on the type and localization of the tumor. Diagnosis of the disease includes radiography and CT, examination of bone marrow biopsies, clinical and biochemical blood tests. Radiation therapy, polychemotherapy, and complex rehabilitation are used for treatment.
In clinical hematology, plasmocytoma refers to paraproteinemic leukemias. It occurs with a frequency of about 3 cases per 100 thousand population, but the prevalence of the disease increases dramatically with age ‒ up to 37 cases per 100 thousand elderly people. The average age of patients diagnosed with a tumor is 55-74 years. Men make up 61% of all patients. Persons of the Negroid race are more susceptible to the disease. Among the tumor processes of the hematopoietic system, all types of plasmocytoma account for 10-14%.
The etiological structure of plasma cell tumors has not been precisely established. An important role in the development of the disease is given to prolonged antigenic stimulation of immune cells against the background of chronic infections, autoimmune diseases, exposure to exogenous toxins and radiation. The genetic predisposition to the occurrence of paraproteinemic tumors has been proven. The risk of developing the disease increases in people with chromosomal aberrations.
Age is recognized as the main unmodified risk factor for plasmocytoma. Single (solitary) tumors are more typical for patients of the pre-retirement age of 55-60 years, about 30% of cases of the disease develop among people younger than 50 years. The generalized form of the disease has an age median of about 70 years, only in 35% of people it is detected before the age of 65. The modifiable predisposing factors include occupational hazards, living in regions with an unfavorable environmental situation.
Paraproteinemic hemoblastoses, which include plasmocytoma, are tumors from a single clone of B-lymphocytes. Under the influence of provoking factors, a malignant transformation of the primary cell occurs, from which a line with similar mutations and the ability to unlimited division is formed. The neoplasm secretes a certain type of immunoglobulins, the presence of which is the basis for diagnosis.
Pathomorphologically mutant B lymphocytes are characterized by pronounced polymorphism and atypia, the presence of abnormal cell nuclei, large nucleoli. A characteristic feature is considered to be a “flaming” cytoplasm with multiple inclusions. Cytological differences of plasma cells are more pronounced in poorly differentiated variants of the tumor.
There are several options for the systematization of neoplasms. According to the degree of maturity of mutant cells, there are high- and low-differentiated plasmocytomas. According to immunohistochemical features, A-myeloma, D-myeloma, G-myeloma are distinguished. The most important classification is based on clinical and morphological characteristics, according to which two types of plasmocytoma are distinguished:
- Solitary. It makes up to 5% of all tumor formations, characterized by the presence of local proliferation of clonal plasma cells. It is recognized as a prognostically favorable variant of the disease.
- Generalized (multiple myeloma). It is characterized by uncontrolled proliferation of B-lymphocytes in various organs and tissues of the body, develops against the background of chromosomal disorders and pathology of the stromal environment. A common form, which is up to 1% among all malignant neoplasms.
Single paraproteinemic tumors are further divided into two subgroups: solitary bone plasmocytoma (SPC) and extramedullary plasmocytoma (EMP). SPC occurs 2-5 times more often than EMP. The bones of the spine (42-61%), pelvis (15%), ribs (12%) are mainly affected. Among extramedullary neoplasms, up to 85% are located in the head and neck area, it is also possible to involve the lungs, gastrointestinal organs, and the urogenital tract in the process.
Clinical manifestations of solitary neoplasm are determined by the location of the tumor focus. When bone tissue is affected, localized pain syndrome comes to the fore, which constantly bothers the patient, has no clear connection with physical exertion or a change in body position. With compression of nearby nerve structures, neuropathies and radiculopathies develop, which are characterized by shooting pains, sensitivity disorders.
The leading symptoms in EMP are signs of lesion of ENT organs, which is associated with the typical localization of the tumor. Patients complain of nasal congestion, which is not stopped by vasoconstrictive drops, periodic nosebleeds, the formation of dry crusts in the nasal cavity. Less common are hoarseness of voice, difficulty swallowing, hearing loss and ear pain.
EMP in the lower respiratory tract manifests episodes of shortness of breath against the background of bronchial obstruction, prolonged cough, heaviness and chest pain. When an extramedullary plasmocytoma is located in the abdominal cavity, nonspecific abdominal pain, chronic constipation, nausea and vomiting occur. Paraproteinemic tumor of the urogenital tract is manifested by disorders of urination, the appearance of blood in the urine, pain in the lower back.
Multiple myeloma in 10-20% of cases is asymptomatic, manifest variants of the disease are characterized by various combinations of the above-described signs. Most often there are pains in the spine, sternum and ribs, which are accompanied by pathological fractures and osteoporosis. Patients are concerned about dyspeptic and dysuric disorders, minor hemorrhages in the skin, gastric, nasal and pulmonary bleeding.
In 60% of patients with multiple myeloma, a moderate or severe degree of anemia is detected, which is accompanied by hemic hypoxia. In 50-90% of cases, renal pathology is associated, which is one of the main reasons for reducing the life expectancy of patients. Against the background of acquired immune insufficiency, recurrent and generalized infections of the respiratory and urinary tract develop.
With plasmocytoma, hyperproduction of monoclonal immunoglobulins is observed, which causes amyloidosis of internal organs. An extramedullary tumor can cause mechanical jaundice, intestinal perforation, and inter-loop fistula. When tumor masses appear in the neck, compression of the respiratory tract occurs, which in some cases causes asphyxia and requires urgent medical care.
The examination of the patient is carried out by an oncogematologist. Diagnostic measures begin with the collection of complaints, clarification of the conditions for the appearance of symptoms, physical examination with palpation of painful areas of the body. Detection of paraproteinosis requires a comprehensive health examination, which includes the following laboratory and instrumental methods:
- X-ray diagnostics. In case of bone pain, chest x-ray, spine and extremities is prescribed, with the help of which volumetric neoplasms are determined. To accurately visualize tumors and determine the extent of the process, a CT scan of the affected area of the body is performed. The PET-CT technique is indicated for the diagnosis of generalized plasmocytoma.
- Bone marrow biopsy. With a solitary form, a normal cytological picture is found. In multiple myeloma, more than 10% of plasma tumor cells are detected in the results of the study. In case of solitary neoplasms, it is advisable to conduct a biopsy of tumor tissue for histological diagnosis.
- Blood test. With a plasmocytoma, a decrease in hemoglobin levels of less than 100 g / l, an increase in ESR, and the adhesion of red blood cells in the form of “coin columns” is detected. Less common are leukopenia and thrombocytopenia. Hypercalcemia is detected in 20-40% of patients.
- Immunological diagnostics. The pathognomonic sign of the disease is serum monoclonal M-protein (paraprotein). To clarify the diagnosis, the type and class of immunoglobulins in blood serum and urine samples are determined. To determine the degree of maturity of the plasmocytoma, immunohistochemical studies of tumor biopsies are prescribed.
When making a diagnosis of “solitary plasmocytoma”, it is necessary to conduct a thorough assessment of instrumental data, since multiple myeloma is often detected during differential diagnosis. During the examination, it is necessary to exclude:
- Ewing ‘s sarcoma;
- monoclonal benign gammapathies;
- Waldenstrom ‘s macroglobulinemia;
- chronic glomerulonephritis.
Malignant plasmocytic cells have a high sensitivity to radiation, therefore, with solitary neoplasms, local radiation therapy is the method of choice. It contributes to the stabilization or regression of plasmocytoma in 80% of patients. X-ray markers of the effectiveness of treatment are considered to be sclerosis and remineralization of the affected bone tissue. Course radiation therapy is performed in all patients with multiple myeloma.
An effective treatment for plasmocytoma is polychemotherapy, which shows the best results in patients under 65 years of age without severe concomitant diseases. Treatment is aimed at the maximum possible reduction of the clone of tumor cells. For chemotherapy of a plasmocytic tumor, 5 classes of drugs can be prescribed:
- alkylating agents;
- proteosome inhibitors;
- immunomodulatory drugs;
Surgical intervention is considered as a method of choice for solitary plasmocytoma, which is located in an accessible place for removal. Excision of the main volume of tumor cells improves the function of the affected organ or bone, increases the effectiveness of radiotherapy. In case of pathological fractures, the help of an orthopedic traumatologist is required for the reposition of bone fragments, the optimal method of osteosynthesis.
Despite the improvement of treatment methods, the average survival rate for generalized plasmocytoma is about 3 years. Patients in the terminal stage of the disease are shown palliative treatment, which includes adequate doses of narcotic analgesics and other painkillers, prevention and treatment of infectious complications, distant radiation therapy. Patients need care within specialized hospitals.
All patients with plasmocytoma require dispensary observation by an oncogematologist throughout their lives. To improve the quality of life, a comprehensive rehabilitation program is selected, which includes symptomatic treatment, blood clotting control, the use of orthoses to improve the function of the musculoskeletal system. Much attention is paid to psychosocial rehabilitation.
Prognosis and prevention
The effectiveness of treatment and life expectancy depends on the form and severity of paraproteinosis. Generalized plasmocytoma is considered a prognostically unfavorable disease, especially in combination with severe myelodepression, rapid tumor growth, and a rapid increase in serum paraprotein levels. Given the unclear etiology, effective prevention measures have not been developed.