Malignant lymphoma of the breast is a malignant tumor that occurs in the lymphoid tissue of the breast, usually in the absence of a previous history of lymphoma, with a primary origin in the breast and an onset confined to the breast and regional lymph nodes. The incidence of primary breast lymphoma is very rare and has been reported to account for only 0.09% to 0.53% of breast malignancies, but many types of lymphoma can occur in the breast, the vast majority of which are non-Hodgkin’s malignant lymphomas, with B-cell lymphoma predominating.
What factors are associated with the development of malignant lymphoma of the breast?
The cause of malignant lymphoma of the breast is unknown, but studies have found that its development may be associated with the following risk factors.
- Environmental factors. For example, radiation damage, a higher than normal incidence of lymphoma in people who receive long-term treatment with radioactive materials and radiation, and an increased risk of disease in people who are closely exposed to certain industrial chemicals.
- EB virus infection. Higher levels of EBV antibodies are found in about 8% of patients with lymphoma, so it is thought that the development of malignant lymphoma may be related to EBV infection.
- Immunocompromised. Patients with primary immunodeficiency disorders are at increased risk for malignant lymphoma of the breast, which may be associated with abnormal proliferation of lymphocytes due to impaired immune regulation leading to loss of control.
- Genetic susceptibility. Chromosomal abnormalities are commonly seen in patients with lymphoma, with occasional reports of familial development and an increased risk of disease in siblings of patients.
What are the manifestations of malignant lymphoma of the breast?
Malignant lymphoma of the breast often develops at a young age and can occur unilaterally or simultaneously in both breasts, and is rare in men.
The symptoms of malignant lymphoma of the breast are similar to those of breast cancer. They are usually one or more scattered painless, movable masses in one or both breasts that grow rapidly, have clear borders, are tough, and are not adherent to the skin, and the skin on the surface of the mass may have cyanotic changes, with or without axillary lymph node enlargement or hepatosplenomegaly.
How is malignant lymphoma of the breast diagnosed?
It is difficult to confirm the diagnosis of malignant lymphoma of the breast based on presentation and imaging, and doctors usually differentiate it from other tumors of the breast and breast hyperplasia, inflammatory breast cancer, and inflammatory breast disease. The doctor will consider the possibility of this disease if he finds a fast-growing lump in the breast with clear borders, tough texture, movable and cyanotic skin changes on the surface of the lump, and will further examine in detail the superficial and deep lymph nodes and the liver and spleen for enlargement to exclude systemic malignant lymphoma.
Pathologic examination is an important basis for confirming the diagnosis, providing sufficient specimens of tumor tissue by lesion aspiration or surgical biopsy. However, puncture often yields only a relatively small number of tumor cells and does not allow for a more definitive classification. If the breast mass is large, surgery is still the better choice. For those with axillary lymph node involvement, a lymph node biopsy is also an important diagnostic tool.
Conventional imaging such as mammography, ultrasound, and magnetic resonance imaging (MRI) are difficult to distinguish from other tumors of the breast, but physicians still use appropriate imaging and bone marrow aspiration to clarify clinical staging.
How is malignant lymphoma of the breast treated?
Early and reasonable treatment can improve outcomes, so treat aggressively once diagnosed.
Doctors often use a combination of chemotherapy, radiation therapy, surgery, and targeted therapy. Surgery alone is far from sufficient as it provides a specimen that helps to determine a clear diagnosis and further staging of the tumor by the pathologist, and also removes the tumor, but does not significantly improve survival or reduce the risk of recurrence. Chemotherapy plays a pivotal role in the treatment of malignant lymphoma of the breast because of the predominant transmission through blood and invasion of adjacent lymph nodes. The choice of chemotherapy regimen is mainly based on pathological staging, etc. Radiotherapy is also an important treatment, but the use of radiotherapy depends on the type and stage of the patient’s disease. Some patients may also receive targeted therapy.
The overall outcome of malignant lymphoma of the breast is poor, with good outcomes for those with lesions confined to one breast who receive combination therapy and poor outcomes for those with lesions in both breasts or with concomitant (or metastatic) lymphadenopathy. Histologic type is a major factor affecting outcome, with nodular types usually having a better outcome than diffuse types and well-differentiated small cell types having a better outcome than poorly differentiated large cell types. Staging is also a key factor in outcome, with worse outcome the later the staging.