Malignant lymphoma is a neoplasm which originates in lymph tissue. It is not actually breast cancer, but can be difficult to distinguish from breast cancer in the early stages of disease. The early breast cancer screening mammography indicators for potentially malignant breast cancer are quite similar to malignant lymphoma, and as a result, malignant lymphoma of the breast is often misdiagnosed as breast cancer. A primary non-Hodgkin's lympoma of the breast is a very rare occurance, accounting for only about 0.1 to 0.5 % of all reported malignant breast tumors. Most patients who develop primary breast lymphoma will also develop metastasis to other regions of the body. There are various kinds of lymphomas, but the most common breast lymphoma is the B cell non-Hodgkin's lymphoma. In terms of clinical prognosis, an early diagnosis of a low grade or stage I lymphoma will generally give the best outlook.
A majority of patients with breast lymphoma present with a localized intermediate-grade lymphoma, and most cases presenting with disseminated disease actually have a low-grade lymphoma. On average, patients presenting with breast lymphomas are split between stage I and stage II tumors about 50% of the time. The average age of development for a breast lymphoma seems to be about 57 years. Lymphoma of the breast can develop in a younger women, but on the whole it is a disease that mostly affects older women.
In the clinical setting, a breast lymphoma might present as elastically firm, well-defined, and often multiple tumors. There might be other symptoms going on in other areas of the body, however. A women with lymphoma might also present with a marked but painless swelling of the thyroid, (indicating a more systemic disease state.) The most common symptoms of breast lymphoma are a painless breast mass, most frequently located in the outer quadrants ( and usually in the right breast, for some reason)
Mammography of a breast lymphoma might reveal a homogeneous density with regular borders, but without microcalcificaton or spiculation. Sometimes one just sees a faint 'tumor shadow'.
An ultrasonogram of lymphoma of the breast might typically reveal a coarse internal echo, a hypoechoic mass with an irregular border and occasionally a lobulated mass representing a very large tumor. The most likely ultrasound image for a breast lymphoma will be of a heterogenous lobulated hypoechoic mass.
Sometimes MRI can help detect a malignant breast lymphoma. A primary breast MRI is often visualized as a lobulated lesion with expansive and infiltrating features. However, breast MRI findings on lymphomas are quite non-specific. Still, breast MRI can help in the diagnosis and treatment of a breast lymphomas in that it can help determine the extent and number of lesions, and in finding any cutaneous, subcutaneous or nodal involvement of the contralateral breast.
Although the various imaging characteristics of a given breast tumor may suggest the possibility of breast non-hodgkin's lymphoma of the breast, none of the findings are pathognomonic. The imaging pattern of breast lymphoma is unrelated to its histopathologic subtype, and in fact, only a very small number of patients ultimately diagnosed with lymphoma of the breast actually present with clear B-cell lymphoma symptoms.
Histologically, breast lymphoma-tumors tend to infiltrate between mammary ducts, but do not tend to destroy them. Interestingly, it is actually quite difficult to distinguish malignant breast lymphoma from breast in the early stages, even when examining exisional biopsy and fine needle biopsy samples. Only when the disease really takes hold and one finds the clear presence of diffuse large B-cells can one make a definitive diagnosis. Most breast lymphomas are initially diagnosed as breast carcinoma, because that is what they appear to be. It usually takes a really high-power microscopic view to see the B-cells of breast lymphoma in evidence. When they are present, one might typically see an abnormal lymphoid population of small to medium sized centrocyte-like B-cells and monocytoid B-cells.
The therapeutic management of breast lymphoma is not as fully established as the treatment options for breast cancer, and some aspects remain a bit controversial. The first treatment priority for breast lymphoma is of course to determine whether the disease originates in the breast, or is systemic in nature. There are many different kinds of lymphoma, too many to be discussed here, but the kinds of lymphoma that form soft tissue masses in unusual locations such as the breast are generally more problematic to treat. However, there is usually some positive response to treatment.
The three main options for treatment are similar to breast cancers. Patients are usually treated either by surgical intervention alone (for localized breast tumors), surgery with chemotherapy, or surgery with radiation therapy and chemotherapy, a so-called multi-modal approach. Quite often, chemotherapy is withheld until there is evidence of a relapse, or, until there is evidence that the lymphoma is systemic in nature. Some breast lymphomas may be treated without surgery and just with radiation therarpy, and these tumors do tend to have the best prognosis, likely because the presentation was mild enough and found early enough that surgery and chemical therapy were not indicated.
Another intensive treatment option for breast lymphoma, should circumstances indicate, is to include high-dose chemotherapy supported by peripheral blood stem cell transplantation, but the use of stem cells is very controversial and not widely discussed. Essentially what happens in these more intensive types of treatment is that first a bone marrow sample is taken. Then, the physicians attempt to grow stems cells from the bone marrow in a laboratory setting. In the chemical treatment of the breast lymphoma, the lymphoma is 'poisened', which kills it, but this will often kill the patient's bone marrow as well. So, the doctors may then attempt to 'rescue' the damaged bone marrow by putting the saved sample, along with the newly grown stem cells, back into the patient.
Overall, breast lymphoma has a poor prognosis, and while there is still a good deal of success, the disease-free recover rates are in general quite a bit lower than for breast cancer. Without any kind of adjuvant therapy, the relapse rate for breast lymphomas treated by surgery alone is fairly high, and relapse can even occur up to ten years following breast surgery. However, no discernible factors, including stage or histologic findings, appear to consistently effect the recurrence rate. But generally, if a patient survives the early treatment phase of the disease, they tend to do very well.
Statistically, it would seem that about 35% of patients with lymphoma of the breast are treated by surgery and chemotherapy , and about 36% treated with surgery and chemotherapy and radiation, and about 20% treated by surgery with radiation. A smaller percentage, about 6%, are treated with surgery alone, and another very small subgroup is treated by radiation therapy alone.
The rates of complete remission of lymphoma of the breast tend to be around the 50% range, with a slightly higher success ratio for patients treated with surgery and chemotherapy. (Statistics regarding the success rates for different treatment modalities tend to be quite variable- the average success rates are about the same, but the 'best' treatment methods are not consistenly demostrated across many studies.) However, it must be remembered that the choice of treatment will usually depend upon many circunstances, including the health of the patient and the severity of the disease at the time of presentation. Unfortunately, the survival rates for breast lymphoma are not all that promising. It can be estimated that about 30% to 50% of patients with lymphoma of the breast will survive beyond two years. The overall survival rates are slightly higher for patients treated with surgery and radiation therapy without chemotherapy, but one cautions that the use of chemotherapy is usually indicated when the disease is already at a more advanced or systemic state, so those statistics can be misleading. However, it does appear that for patients who succumb to the disease, closure tends to occur in an average for seven months or so rather than a prolonged battle. So, if a patient with breast survival can survive beyond one to two years, chances are that the disease is in remission.
Generally speaking, the prognosis for breast lymphoma seems to be related to the histologic type and stage of the disease. If a breast lymphoma is graded as stage II, then the overal survival rates seem to be just below 30%, while the prognosis for stage I tumors is much better, with overall survival rates or 'freedom from probable progression' around 60%.