Guidelines on Diagnosis and Treatment of Malignant Lymphomas

Mantle Cell Lymphoma
Definition and incidence
Mantle cell lymphoma (MCL) is a B-cell neoplasm composed of
monomorphic small to medium sized lymphoid cells with irregular
nuclei which most closely resemble centrocytes/ follicle centre
cells but with less-irregular nuclei. MCL accounts for 3-10% of
non-Hodgkin lymphomas, occurring predominantly in middleaged
or older individuals (median age 63) with an incidence of
0.72 cases/100,000/year and a male: female ratio of 5:1.
ICD – O Code 9673/3
Clinical Presentation
Patients usually present with enlarged lymph nodes at multiple
sites and frequently a massively enlarged spleen. Bone marrow
involvement with occasional leukaemic spill is present in 80% of
patients. Waldeyer’s Ring and the gastrointestinal tract are
frequent extra-nodal sites of involvement. Lymphomatous
polyposis of the gastrointestinal tract is a form of mantle cell
lymphoma and can occur as variably-sized polyps in any part of
the gastrointestinal tract.
Pathology and Genetics
MCL shows architectural destruction by a monomorphic
lymphoid proliferation with a vaguely nodular or mantle zone
growth pattern. Many cases have scattered single epithelioid
histiocytes which can produce a ‘starry sky’ appearance.
Hyalinized small blood vessels are commonly seen. Disease
progression or relapse is characterised by an increase in nuclear
size, pleomorphism, nuclear chromatin dispersal and an increase
in mitotic activity. Blastoid variants with cells resembling
lymphoblasts and a high mitotic index are associated
with a worse prognosis.
Immunophenotype
The neoplastic cells are monoclonal B-cells with intense surface
IgM+/- IgD. They are CD19+ve, CD20+ve, CD5+ve, FMC7+ve
and CD10-ve and express Cyclin D1. Cases with gastrointestinal
involvement express the alpha4B7 homing receptor.
Genetics
MCL is defined by the presence of the t(11;14)(q13;q32)
resulting in juxtaposition of CyclinD1 and the IgH gene which
leads to upregulation of CyclinD1. The translocation can be
detected reliably by FISH and in about 40% of cases by PCR.
Staging
Staging of disease, if nodal, can be reported using the Ann Arbor
classification, but is clearly not appropriate for extranodal
presentation such as multiple lymphomatous polyposis.
Recommended Investigations
Generic: see page 2
Specific
Gastrointestinal endoscopy (if appropriate)
BMA and trephine, with immunophenotyping
and FISH / PCR if marrow involved.
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