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Author: Hannah Woo, Final year medical student, The University of Auckland, New Zealand. Editor in Chief: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. August 2017. Copy Writer: Gus Mitchell. September 2017.
Cutaneous marginal zone lymphoma is a type of low-grade cutaneous B-cell lymphoma originating from the mucosa-associated lymphoid tissue (MALT). It is a heterogeneous proliferation of marginal zone cells, B-cells, small lymphocytes, and plasma cells.
Cutaneous marginal zone lymphoma affects all ages, but tends to affect younger patients compared to other types of B-cell lymphoma . The median age of diagnosis is 55 years. Men are twice as likely to get this type of lymphoma than women .
It remains unclear whether cutaneous marginal zone lymphoma is the result of a de novo neoplastic process or a reaction to exogenous and/or endogenous agents . A small number of cases have been associated with Borrelia burgdorferi (the cause of Lyme disease), and Hepatitis C infection [1–4].
Cutaneous marginal zone lymphoma presents as papules, plaques, or nodules that range in colour from red to violet. The lesions may be solitary or multifocal, and are most commonly seen on the trunk or arms [1,2,4].
After obtaining a full history, physical examination, and skin examination, the diagnosis is made based on an adequate full-thickness biopsy of affected skin.
A 4–6 mm punch, incisional, or excisional biopsy should be obtained. The biopsy specimen should include the reticular dermis and fat .
Histologically, cutaneous marginal zone lymphomas show nodular to diffuse dermal infiltration of marginal zone B-cells, lymphocytes, lymphoplasmacytoid cells, plasma cells admixed with centroblast- or immunoblast-like cells, and reactive T cells. The marginal zone B-cells are small to medium in size and have irregular nuclei, inconspicuous nucleoli, and abundant pale cytoplasm .
Immunohistochemistry of cutaneous marginal zone lymphomas are positive for CD20, CD79a, and Bcl-2, and are negative for CD-10, and Bcl-6 .
Other essential investigations include a full blood count, comprehensive metabolic profile, and lactate dehydrogenase studies. A Borrelia burgdorferi titre may be performed, particularly in endemic regions .
Additional blood tests that may be performed for the evaluation and staging of disease include antinuclear antibody, rapid plasma reagin, viral hepatitis serologies, flow cytometry, serum protein electrophoresis, and quantitative immunoglobulin evaluation .
Imaging may include positron emission tomography (PET) and/or computed tomography (CT) .
Any lymph node with high PET activity, or measuring greater than 1.5 cm in length by imaging study, should be biopsied. Bone marrow biopsy is optional .
Differential diagnosis for cutaneous marginal zone lymphoma can include:
It is important to distinguish primary cutaneous marginal zone lymphoma from non-Hodgkin systemic B-cell lymphoma with cutaneous involvement [1,2].
Spontaneous resolution of cutaneous marginal zone lymphoma can occasionally occur, particularly in the first few months . Solitary or localised disease can be treated with radiotherapy or surgical excision, with curative intent [1,5].
Multifocal disease can be treated with:
Patients who develop disseminated skin lesions are treated with multiagent chemotherapy .
Antibiotic therapy may be indicated in patients who are positive for Borrelia burgdorferi antibodies .
The prognosis is excellent, with a 5-year survival rate of up to 99% . The cutaneous relapse rate is high at approximately 40% . Extracutaneous spread of disease is rare .
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