Splenic Marginal Zone LymphomaSplenic marginal zone lymphoma is generally an indolent lymphoma that involves the spleen, bone marrow and other organs. Splenomegaly is usually observed and when localized to the spleen then removal of the spleen often results in complete remission.
SMZL is also known as Splenic Lymphoma with Villous Lymphocytes. (villous means having the appearance of being covered with fine long hairs) It resembles hairy cell leukaemia and is considered to be the a leukaemic form of lymphoma. It is extremely rare and only accounts for about 1% of all lymphomas.
Diagnosis and PrognosisSMZL usually presents with massive splenomegaly, marrow and blood involvement. Patients often have anaemia and lymphocytosis. Overall the prognosis is very good for long term survival, with the median being approximately 13 years. The two most important risk factors are anaemia and lymphocytosis.
Previously a definitive diagnosis could only be made after removal of the spleen, but it has now been established that a conclusive diagnosis can be made from a bone marrow biopsy due to the peculiar intrasinusoidal BM involvement.
Although SMZL is usually CD5 negative some patients are CD5 positive. The following article discusses the various presentations of SMZL Splenic marginal zone lymphoma: hydra with many heads?
Here is another study that looks at CD5 + SMZL
There is no currently accepted International Prognostic Index for SMZL like there is for some other types of non-Hodgkin's lymphoma. Nevertheless there are recognized risk factors which may form the basis for an IPI in the future. There are three risk factors:
0 risk factors = Low risk, 88% 5 year cause specific survival (CSS) 1 risk factor = intermediate risk, 73% 5 year CSS 2 or more risk factors = high risk, 50% 5 year CSS
Splenic marginal zone lymphoma: a prognostic model for clinical use
Splenic marginal zone lymphoma a review - from the journal Blood
TreatmentsOptimal treatment has not yet been established but past studies indicate that splenectomy may prove more beneficial than chemotherapy in terms of survival. Prognostic features of splenic lymphoma with villous lymphocytes:
However in the era of Rituximab data is beginning to show that Rituximab monotherapy may be the preferred upfront treatment of choice. This may be an option that many patients prefer because it means they keep their spleen. Here is a study from the 2011 ASH convention showing the extremely good results of Rituximab and the suggestion it may be a better choice than spenectomy. Treatment of Splenic Marginal Zone Lymphoma with Rituximab Monotherapy in 59 Patients
From the ASH education series, a review of marginal zone lymphoma treatments. Marginal Zone Lymphomas: Management of Nodal, Splenic, and MALT NHL
When chemotherapy stronger than just Rituxan monotherapy is required the purine analogues such as Pentostatin (2-deoxycoformycin), 2-CDA (2-chlorodeoxyadenosine) and Fludarabine appear to be more effective than the alkylating agents such as Cyclophosphamide, although combination chemotherapy is also common.
Another option that is being explored as an alternative to splenectomy is Pentostatin. It has show significant success in both untreated and relapsed patients, who are not candidates for surgery.
The following is a full review of the treatments of Splenic lymphomas. How I diagnose and treat splenic lymphomas
Other information
Further information about SMZL can be found at Pubmed. Just click the link below.
A focused search about Splenic Marginal Zone lymphoma from PubMed
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