Disease >> Oncology >> Medical Oncology

Plasmacytoma

Introduction
Cause
Prevention
Complication
Symptom
Examine
Diagnosis

Introduction

Introduction to plasma cell tumor Plasmacytoma is a primary and systemic malignant tumor originating from the bone marrow. It is derived from B lymphocytes and has the property of differentiating into plasma cells. Isolated solitary cell tumors are rare and can be cured. Among them, multiple plasmacytoma is the most common, characterized by osteolytic lesions and plasma cells infiltrating the bone marrow. In addition, it is often accompanied by anemia, hyperglobulinemia, hypercalcemia, impaired renal function and susceptibility to infection. basic knowledge Sickness ratio: 0.05% Susceptible population: after 40 to 50 years old Mode of infection: non-infectious Complications: anemia, hypercalcemia, swelling, hyperuricemia, amyloidosis, giant tongue, uremia

Cause

Plasma cell tumor etiology

Infection and physical and chemical factors (35%)

Nowadays, humans only know some predisposing factors, such as high dose of ionizing radiation, chronic antigenic substance stimulation and viral infection can cause disease. The disease can also occur in the late stages of chronic diseases caused by consumptive bacterial infections such as chronic osteomyelitis, pyelonephritis, and tuberculosis.

Reduced immunity (15%)

The incidence of the elderly has increased significantly, suggesting that the basic process is related to immune function and aging. The immune senescence is most evident in the T cell line and is consistent with thymic degeneration. The multi-step tumor-causing pattern is: first, thymic degeneration (which may also be degenerate), and loss of control of early B cell development, including abnormal cytokine production; and second step, abnormal polyclonality due to loss of normal regulation Proliferation; the third step is to increase the chance of random gene mutations in the proliferation of clones to cause malignant transformation.

Genetic factors (5%)

Family factors have also been reported.

Pathological change

1. Visible to the naked eye: Myeloma is similar to a tumor composed entirely or almost completely. It is gray or red, soft, and has a myeloid shape. Sometimes it can be a liquid change. The tumor tissue invades the medullary cavity and can form. Round tumor nodules, and gradually enlarge, fusion, partial disseminated lesions and most of the single lesions can form huge tumor mass, often bleeding, cystic changes and necrosis changes, tumor tissue invading cortical bone Expanding outward, in the spine, tumor swelling can compress the spinal cord and nerve roots.

2. Microscopically: Tumor tissue consists of dense clusters of cells with few intercellular matrices. Tumor cells can be identified as plasma cells. At least some tumor cells can be identified as plasma cells. These cells are rich in cytoplasm, dark-stained, basophilic, with clear boundaries, rounded nucleus, eccentricity, and clear nucleus. Peripheral halo (a very well-developed Golgi), chromatin is blocky, clearly facing the nuclear membrane (wheel or leopard skin-like nucleus), sometimes under the electron microscope in the cytoplasm or outside the cytoplasm can be seen square or triangular Crystallization, some bulky cells around these more or less typical plasma cells, may have binuclear, visible mitotic figures, tumors with the above characteristics are well-differentiated plasmacytomas. In the remaining cases, the cells of the tumor are highly atypical, very atypical, mainly composed of large cells or giant cells, deeply stained with cytoplasm, can have a large number of vacuoles, and the nucleus has obvious polymorphism with staining. Excessive, large nucleoli, visible pathological division, visible giant cells containing several nuclear or heterogeneous nuclei, these atypical cells scattered in the well-differentiated cells that can be identified as plasma cells.

Prevention

Plasma cell tumor prevention

1. Develop good habits, stop smoking and limit alcohol. Smoking, the World Health Organization predicts that if people no longer smoke, after five years, the world's cancer will be reduced by 1/3; secondly, no alcohol. Smoke and alcohol are extremely acidic and acidic substances. People who smoke and drink for a long time can easily lead to acidic body.

2. Don't eat too much salty and spicy food, don't eat food that is overheated, too cold, expired and deteriorated; those who are frail or have certain genetic diseases should eat some anti-cancer foods and high alkali content as appropriate. Alkaline foods maintain a good mental state.

Complication

Plasmacytoma complications Complications anemia hypercalcemia swollen hyperuricemia amyloidosis giant tongue uremia

Often accompanied by anemia, hyperglobulinemia, hypercalcemia, impaired renal function and predisposition to infection.

During the progression, there may be swelling of superficial bone (ribs, sternum, clavicle), progressive weight loss, anemia, fever, high blood nitrogen, bleeding tendency, hypercalcemia and hyperuricemia, extra-osseous tumors and starch The giant tongue caused by degeneration, a few cases have renal insufficiency, severe cases can cause uremia.

Symptom

Symptoms of plasmacytoma Common symptoms Spinal cord compression, bone marrow plasma cell enlargement, radiation pain, high blood nitrogen, hypercalcemia, proteinuria, amyloidosis, diffuse, low back pain, hyperuricemia

The incidence rate is very high, and the incidence rate of osteosarcoma is higher than that of men. The ratio of male to female is 1.5:1. It occurs in adults or the elderly. It usually occurs after 40 to 50 years old. It is rare before 30 years old. Before puberty.

Skin plasma cells are most common in myeloma or in the metastasis of primary plasmacytoma of other tissues. This type of case is called secondary cutaneous plasmacytoma, which can also be directly spread by bone damage underneath. Secondary granulosa cell tumor has a poor prognosis. The rarer one is single or multiple skin lesions. It is found in any other tissues that are not affected. The bone X-ray and bone marrow biopsy are normal, but the skin damage can produce a monoclonal Protein, this kind of skin damage is called primary dermal plasma cell tumor. In some cases, the skin damage is resolved by treatment, never relapse, the prognosis is good, and some patients develop myeloma, primary and secondary plasma cells. The appearance of skin lesions in both tumors is non-specific, manifesting as skin color, red or purple dermis or subcutaneous nodules.

Plasmacytoma is a systemic tumor that originates in the bone marrow. Sooner or later, it involves most of the bones of the body, especially in the adult stage of red bone marrow. These areas are the spongy bones of the trunk, the metaphyseal ends of the skull and long bones. Especially the sponge-like bone around the hip and shoulder joints.

Skeletal dissemination of plasmacytoma is not simultaneous and is not consistent. At some stage of plasmacytoma, some bones are easily invaded, while others are not, or their lesions can only be seen under a microscope.

It is not uncommon for a plasmacytoma that is limited to a single segment of the disease at the beginning of the disease. This plasmacytoma is a single plasma cell. Although a single lesion can last for several years, a single lesion with a single lesion remains. Rarely, almost all bones will spread and cause death. The most common site of single plasmacytoma is the spine (one or two vertebral bodies), followed by the trunk bone and the proximal femur.

The initial symptoms are vague or unclear and can last for weeks or months, including mild bone pain, weakness, weight loss or mild anemia. Patients often complain of lower back pain and can spread to the chest and spinal pain. Often aggravated by exercise, paravertebral muscles can contract, slamming spinous processes can induce pain, some cases of low back pain, multiple myeloma tumor tissue can compress nerve roots, triggering sciatic nerve or foot radiation pain, in mild trauma Or without obvious incentives, spinal pain can become very intense, which is a sign of pathological vertebral fractures. When the vertebral body is extensively violated, it may end with gradual or sudden spinal cord compression, with or without With vertebral compression fractures.

Pain and pathological fractures are not common in the first symptoms, and these symptoms occur more frequently in the obvious stage of the tumor.

Examine

Plasmacytoma examination

I. Laboratory inspection

Bone marrow smear

In the early stage of plasmacytoma, when the diagnosis is not clear, the bone marrow smear can often be diagnosed, but the negative can not exclude the possibility of plasmacytoma. If the smear has 3% plasma cells, the possibility of plasmacytoma should be suspected; There is a 10% chance of plasmacytoma, but it can also cause diffuse or increased plasma cells in the bone marrow around the metastasis due to liver infection or cancerous bone metastases; if the percentage of plasma cells is higher, Up to 70%, and there are abnormal plasma cells next to typical plasma cells, such as plasma cells containing large or dual nuclei, or immature, atypical plasma cells, which can be diagnosed as plasmacytoma, the course of plasmacytoma. The more progress, the higher the positive rate of cytology.

2. Serum protein

In most cases, serum globulin increased and albumin/globulin ratio was inverted. Even if the total globulin was not increased, immunoelectrophoresis showed a narrow and sharp peak in the alpha or gamma globulin band due to the monoclonal immunoglobulin. Due to the increase of protein, the electrophoretic changes are almost in all disseminated cases, but there is no change in the early stage of the lesion, especially in single plasmacytoma. In a few cases, serum electrophoresis is not performed, and urinary electrophoresis Have performance.

3.Bence-Jones proteinuria

It is sensitive to urine protein electrophoresis and immunoprotein electrophoresis. It is more sensitive than the traditional method of heating urine. The positive rate of Bence-Jones proteinuria is not high. It can be seen in plasmacytoma (K chain or L) that secretes light chain globulin. Chain) cases.

4. Hypercalcemia

Myeloma hyperplasia can often cause diffuse bone resorption, leading to elevated blood calcium.

Hyperuricemia and azoemia are common. Hyperuricemia is caused by strong nucleic acid metabolism and can occur in all patients with excessive bone marrow hyperplasia. Hypercalcemia is caused by kidney damage of myeloma.

5. Peripheral blood changes

It is characterized by anemia, and there is no change in white blood cells. However, in rare cases, there are obvious leukocytosis and even a large number of plasma cells. Such cases are considered to be plasma cell leukemia.

2. X-ray film

There is an incubation period in the imaging performance. The lesions are disproportionately disproportionate to the extent of the image. Even if the tumor tissue has diffused into the marrow cavity, the trabecular bone and cortical bone are not absorbed, and the image is negative.

Myeloma tumor tissue can destroy the bone tissue with obvious porous changes, and the image shows extensive osteoporosis and cortical bone thinning, especially in the early stage of the lesion and the tumor invades the spine.

In the advanced stage of myeloma, the tumor tissue can not only invade the medullary cavity extensively, but also form an invasive tumor nodule. The newly formed tumor nodule is small in size, and then enlarged and can be fused. These pathological changes determine the plasma cell. Typical imaging findings of the tumor, which are characterized by tiny worm-like, round-point lytic bone, foamy after fusion of the osteolytic zone and extensive extensive osteolytic lesions. There is no hardened margin around the typical osteolytic cavity. At the same time, the tumor tissue can erode the cortical bone inside the bone, making it thinner, and some areas can disappear.

The skull can have a porous change, very small, like a cluster of needles, showing a ground-glass image, such as the further development of the lesion, there may be more disseminated circular dissolving bones of varying sizes, which progressively increase, and It can be fused, and the osteolytic area is a typical piercing edge, and the image of the skull is foggy.

In the spine, plasmacytoma can be characterized by obvious osteoporosis, vertebral body can undergo compression changes, biconcave deformity, thicker intervertebral space, increased curvature, and osteolytic cavity may exist in severe osteoporosis Gap, typically the osteolytic cavity can also be located in the posterior arch and rib of the vertebral body. The cortical bone of the spine and rib can be very thin, part of it is slightly blister-like expansion, part of the cortical bone can be interrupted, and multiple compressed vertebrae are common. Body, pelvic lesions can have the same changes.

In long bones, plasmacytoma can be expressed as osteoporosis, worm-like destruction and honeycomb, foamy osteolytic bone, tumor tissue invades cortical bone from the inside, making it thin, osteolytic fusion can become larger, destroy cortical bone Pathological fractures occur mainly in the metaphysis, especially in the proximal end of the limbs. In the advanced stage, the backbone can be more or less invaded by the tumor tissue.

In a single plasmacytoma of the bone, the image appears as a confined large osteolytic region, and the osteolytic lesions may be of homologous origin, with or without cortical bone invasion; sometimes by multiple punctate The bone-dissolving lesions are fused together; sometimes the bone is inflated and has a thin soap-like osteolytic cavity.

Bone scans can be negative, and even positive lesions that appear to be large on the image can be positive.

Diagnosis

Diagnosis and differentiation of plasmacytoma

diagnosis

Typical and advanced plasmacytoma are easy to diagnose, but early diagnosis of plasmacytoma is difficult. Plasmacytoma can be painless in the early stages, with only minor or insignificant signs, which can last for months, even years.

Clinically, patients with over 40 years of age have skeletal or diffuse low back pain, fatigue, paleness, and mild weight loss. The possibility of myeloma should be suspected.

For the diagnosis of plasmacytoma, it is often necessary to examine the X-ray films of the skull, spine, pelvis and proximal limbs, bone scan, serum protein electrophoresis and immunoprotein electrophoresis (calcemia, uric acidemia), looking for Bence-Jones Proteinuria protein and 24-hour urine protein electrophoresis (kidney clearance), bone marrow puncture of the sternum and tibia, in cases of obvious osteolysis, cases of spinal cord compression and cases of single plasmacytoma Or needle biopsy.

Serum immunoprotein electrophoresis is the most important diagnostic test. In most cases, globulin abnormalities are shown. Single and diffuse plasmacytoma cases are rarely negative, and urine protein electrophoresis is negative in serum protein electrophoresis. Can be positive.

Bone marrow puncture can be negative in the initial or single lesion of the lesion. The bone marrow puncture results can only show undifferentiated atypical components. If only bone marrow puncture results, it can be misdiagnosed as lymphoma.

According to the clinical manifestations, the characteristics of skin lesions and histopathological features can be diagnosed.

Differential diagnosis