Multiple myeloma (MM) originates from bone marrow plasma cells.
It is a malignant tumor of B-lymphocyte origin, accounting for about 1% of all malignancies and 10% of hematologic malignancies (ranked second); the median age of diagnosis is 62 years, with 85% of cases occurring after the age of 50, and the incidence rate is increasing year by year. It is estimated that the annual incidence in China is about 1/100,000, the median age of onset is 57 years (20-87 years), the peak age of onset is 55-65 years, 10.8% are under 40 years old (significantly higher than the literature in Europe and the United States), and the ratio of men to women is 2.35:1. Lymphoma (NHL) and acute myeloid leukemia (AML); the incidence of MM increased 3.4 times from 1973 to 2003, and the ratio of men to women decreased from 3.6:1 to 1.5:1, with a significant increase in patients over 60 years of age and an increasing trend in peak age; the death rate increased rapidly over 60 years of age and reached a peak over 80 years of age. Thus, as the average life expectancy of the population gradually increases, MM is increasingly becoming a malignant hematologic disease that threatens human life and quality of life.
The clinical manifestations of all MM are based on two causes.
, anemia (chronic disease anemia, myeloma cell infiltration, renal anemia, and other mechanisms), renal damage, and infection.
And the first manifestations reported in the literature are.
(1) bone pain/pathological fractures (55-74%).
(2) Anemia (10-30%).
(3) Bleeding (13.8-20.8%).
(4) Infection (16.9 to 20.9%)
(5) kidney damage (50% of patients present early).
The domestic diagnostic criteria for MM (2007) are.
(1) Plasma cells >15% in bone marrow with protoplasmic or juvenile plasma cells (myeloma cells) or tissue biopsy confirmed as plasmacytoma.
(2) The presence of large amounts of monoclonal immunoglobulins (M component) in the serum.
(3) Extensive osteoporosis and/or osteolytic changes. The diagnosis is made when 2 of the above 3 criteria are met.
MM combined with pleural effusion may have the following mechanisms.
(1) Pleural infiltration by myeloma cells (myelomatous pleural effusion (MPE)).
(2) Infiltration of the pleura by adjacent tumor tissue (extramedullary plasmacytoma).
(3) due to nephrotic syndrome caused by myeloma nephropathy.
(4) from MM combined with lower extremity deep vein thrombosis leading to pulmonary embolism
(5) due to cardiac insufficiency caused by MM in combination with amyloidosis
(6) due to an associated secondary tumor (e.g., lung cancer)
(7) due to lymphatic vessel obstruction caused by tumor infiltration. According to the literature, MM with pleural effusion accounts for only 6%, and MPE accounts for less than 1% of these cases. 80% of these cases are IgA type MM, most of the others are IgG type, and the cases of IgD type MM with MPE are even rarer.
To confirm the diagnosis of MPE, the following conditions should be met.
(1) monoclonal immunoglobulins are visible in the pleural fluid protein electrophoresis.
(2) Abnormal plasma cells (primitive or naive plasma cells) are detected in the pleural fluid.
(3) Histological confirmation of myeloma cell infiltration by pleural biopsy. In this case, although pleural biopsy was not performed, histological diagnosis was achieved by centrifugation of the pleural effusion followed by paraffin embedding and histological sectioning followed by HE staining and histochemical staining, respectively, and the nature of the pleural effusion was determined to be MPE.
So far, MM is still an incurable disease, but with the development of modern medical technology, especially in recent years with the proteasome inhibitor bortezomib (Bortezomib) and new anti-neovascular and immunomodulatory agent lenalidomide and other new drugs, the survival time of MM patients has been greatly extended, the median survival time of more than 5 years The danger of MM lies in its complications such as pathological fracture, severe infection, renal failure, anemia, etc. If early detection, early diagnosis and treatment can delay the emergence of comorbidities and prolong the survival time of patients.
However, the clinical manifestations of MM are complex and insidious, and often involve multiple organ systems.
Therefore, patients are often first diagnosed in different clinical departments, and it is very rare for a patient with pleural effusion as the first manifestation to be finally diagnosed with MM, as in this case. In most cases, patients are first seen in orthopedics for bone pain or even pathological fracture; in nephrology for nephrotic syndrome such as edema and proteinuria; in respiratory medicine for pulmonary infection; in endocrinology for endocrine metabolic disease such as hypercalcemia, hyperuricemia, and combined POEMS; in neurology, ophthalmology, or otolaryngology for hyperviscosity syndrome; or in dermatology. In the case of combined myocardial amyloidosis leading to heart failure, the patient may be seen in a cardiology department; in the case of combined extramedullary plasmacytoma, the patient may be seen in the department of the organ system involved due to the complexity of the tumor invasion site. According to the literature, only 10-30% of all MM patients are first seen in hematology due to anemia. Therefore, it is necessary for physicians in all clinical departments to understand the common clinical manifestations and first symptoms of MM and be alert to avoid misdiagnosis or underdiagnosis.