Primary mediastinal B-cell lymphoma
Primary mediastinal B-cell lymphoma, abbreviated PMBL or PMBCL, is a rare type of lymphoma that forms in the mediastinum (the space in between the lungs) and predominantly affects young adults.[1][2][3]
| Primary mediastinal large B-cell lymphoma | |
|---|---|
 | |
| Micrograph of a primary mediastinal large B-cell lymphoma. H&E stain. | |
| Specialty | Hematology and oncology |
While it had previously been considered a subtype of diffuse large B-cell lymphoma;,[4] the World Health Organization no longer classifies it as such, based on distinct clinicopathologic and molecular features.[5]
Pathophysiology
editPMLBCL arises from a putative thymic peripheral B cell.[6][7] It has several distinctive biological features.[6] Molecular analysis shows that PMLBCL is distinct from other types of diffuse large B-cell lymphomas (DLBCL).[7] MAL gene expression is seen in 70%, unlike other diffuse large B-cell lymphomas.[8]: 370 Gene expression profiling shows considerable variance from other DLBCLs and similarity to Hodgkin disease.[9]: 290–293
PMLBCL is CD20 positive, expresses pan-B markers including CD79a, and has clonal immunoglobulin gene rearrangements and mRNA but paradoxically does not express cytoplasmic or cell surface immunoglobulin.[8]: 370
Clinically, PMLBCL is unusual in several respects. Despite 80% PMLBCL being stage I or II, the presenting anterior mediastinal mass is often over 10 cm and is locally invasive of lung, chest wall, pleura, and pericardium.[6] At initial presentation, PMLBCL is usually confined to mediastinum, but its bulk, rather than additional adenopathy, can sometimes be palpated at the low neck.[6] Increased LDH is seen in approximately 75%,[8]: 370 [6] but unlike other large cell lymphomas, no increase in beta-2 microglobulin is seen even when bulky[8]: 370 which may relate to defective major histocompatibility complex expression.[8]: 370
Diagnosis
editDiagnosis requires a biopsy, so that the exact type of tissue can be determined by examination under a microscope. PMBCL is a distinct type of lymphoma that shares some features with both diffuse large B-cell lymphoma, and nodular sclerosing Hodgkin lymphoma (NSHL).[10] Tumors that are even more closely related to NSHL than typical for PMBCL are called gray zone lymphoma.[10]
Treatment
editMultiagent chemotherapy is recommended, but the preferred regimen is controversial, as is consolidative radiotherapy.[6][11][12][13]
Treatment commonly begins with either R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) or DA-EPOCH-R (dose-adjusted etoposide, prednisolone, vincristine, cyclophosphamide, doxorubicin, rituximab).[14] Other, more intense, regimens may be more effective.[10] PD-1 and PD-L1 inhibitors can be used.[3]
Radiation therapy may be added, especially if chemotherapy does not seem sufficient on its own.[14] Radiation may cause other health problems later, such as breast cancer, and there is some debate about the best approach to it.[10][3]
FDG-PET scanning is not as useful for predicting treatment success in PMBCL as it is in other lymphomas.[10][3]
Prognosis
editMost people with PMBCL 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.[14] Relapses generally appear within 12 to 18 months after the completion of treatment.[10]
Epidemiology
editThis lymphoma is most commonly seen in women between the age of 20 and 40.[10]
See also
editReferences
edit- ^ Johnson PW, Davies AJ (2008). "Primary mediastinal B-cell lymphoma". Hematology. American Society of Hematology. Education Program. 2008: 349–58. doi:10.1182/asheducation-2008.1.349. PMID 19074109.
- ^ Coso D, Rey J, Bouabdallah R (February 2010). "[Primary mediastinal B-cell lymphoma]". Revue de Pneumologie Clinique. 66 (1): 32–5. doi:10.1016/j.pneumo.2009.12.007. PMID 20207294.
- ^ a b c d Yu, Yating; Dong, Xifeng; Tu, Meifeng; Wang, Huaquan (November 2021). "Primary mediastinal large B cell lymphoma". Thoracic Cancer. 12 (21): 2831–2837. doi:10.1111/1759-7714.14155. PMC 8563158.
- ^ "Types of Non-Hodgkin Lymphoma". www.cancer.org. Retrieved 2017-09-28.
- ^ "Primary mediastinal large B-cell lymphoma". ashpublications.org/blood/article/140/9/955/476814/Primary-mediastinal-large-B-cell-lymphoma.
- ^ a b c d e f Armitage, JO; Mauch PM; Harris NL; et al. (2010). "Chapter 21". Non-Hodgkin Lymphomas (2nd ed.). Lippincott Williams & Wilkins. ISBN 9780781791168.
- ^ a b Martelli M, Di Rocco A, Russo E, et al. (2015). "Primary mediastinal lymphoma: diagnosis and treatment options". Expert Rev Hematol. 8 (2): 173–86. doi:10.1586/17474086.2015.994604. hdl:11573/780924. PMID 25537750. S2CID 23040185.
- ^ a b c d e Jaffe, ES; Harris NL; Vardiman JW; Campo E; Arber DA (2011). Hematopathology (1st ed.). Elsevier Saunders. ISBN 9780721600406.
- ^ Sweetenham, J. Lymphomas (Emerging Cancer Therapeutics V3 I2). Demos. November 2, 2012. ISBN 9781936287789
- ^ a b c d e f g Dunleavy K, Wilson WH (January 2015). "Primary mediastinal B-cell lymphoma and mediastinal gray zone lymphoma: do they require a unique therapeutic approach?". Blood. 125 (1): 33–9. doi:10.1182/blood-2014-05-575092. PMC 4281829. PMID 25499450.
- ^ "Non-Hodgkin's Lymphoma" (PDF). Archived from the original (PDF) on May 14, 2005.
- ^ Faris JE, LaCasce AS (2009). "Primary mediastinal large B-cell lymphoma". Clin Adv Hematol Oncol. 7 (2): 125–33. PMID 19367254.
- ^ Dabrowska-Iwanicka A, Walewski JA (2014). "Primary mediastinal large B-cell lymphoma". Curr Hematol Malig Rep. 9 (3): 273–83. doi:10.1007/s11899-014-0219-0. PMC 4180024. PMID 24952250.
- ^ a b c Lees C, Keane C, Gandhi MK, Gunawardana J (February 2019). "Biology and therapy of primary mediastinal B-cell lymphoma: current status and future directions". British Journal of Haematology. 185 (1): 25–41. doi:10.1111/bjh.15778. PMC 6594147. PMID 30740662.