Primary mediastinal B-cell lymphoma, abbreviated PMBL, is a rare type of

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...

that forms in the

mediastinum The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...

(the space in between the lungs) and predominantly affects young adults. It is a subtype of

diffuse large B-cell lymphoma Diffuse large B-cell lymphoma (DLBCL) is a cancer of B cells, a type of lymphocyte that is responsible for producing antibody, antibodies. It is the most common form of non-Hodgkin lymphoma among adults, with an annual Incidence (epidemiology), in ...

; however, it generally has a significantly better prognosis.

Diagnosis

Diagnosis requires a

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...

, so that the exact type of tissue can be determined by examination under a

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...

. PMBL is generally considered a sub-type of

, although it is also closely related to

nodular sclerosing Hodgkin lymphoma Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule, a growth on the roots of legumes * A feature of s ...

(NSHL). Tumors that are even more closely related to NSHL than typical for PMBL are called

gray zone lymphoma Gray zone lymphoma, often presenting as large tumors in the mediastinum, is a type of lymphoma that is characterized by having cellular features of both classic Hodgkin's lymphomas (cHL) and large B-cell lymphomas. Sources * Traverse-Glehen A, Medi ...

Treatment

Treatment commonly begins with months of multi-drug

chemotherapy regimen A chemotherapy regimen is a regimen for chemotherapy, defining the drugs to be used, their dosage, the frequency and duration of treatments, and other considerations. In modern oncology, many regimens combine several chemotherapy drugs in combinat ...

. Either R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) or

DA-EPOCH-R EPOCH is an intensive chemotherapy regimen intended for treatment of aggressive non-Hodgkin's lymphoma. It is often combined with rituximab. In this case it is called R-EPOCH or EPOCH-R.The R-EPOCH regimen consists of: # Rituximab: an anti-CD20 ...

(dose-adjusted etoposide, prednisolone, vincristine, cyclophosphamide, doxorubicin, rituximab) has been typical. Other, more intense, regimens may be more effective.

Radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

may be added, especially if chemotherapy does not seem sufficient on its own. Radiation may cause other health problems later, such as

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

, and there is some debate about the best approach to it.

FDG-PET Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...

scanning is not as useful for predicting treatment success in PMBL as it is in other lymphomas.

Prognosis

Most people with PMBL are successfully treated and survive for many years. However, if the initial treatment is unsuccessful, or if it returns, the long-term prognosis is worse. Relapses generally appear within 12 to 18 months after the completion of treatment.

Diagnosis

Treatment

Prognosis

Epidemiology

See also

References

External links