|Photomicrograph of HE-stained mantle cell lymphoma. Click to enlarge.
||Photomicrograph of cyclin D1 staining of mantle cell lymphoma. Click to enlarge.
Mantle cell lymphoma (MCL) is a distinct subtype of non-Hodgkin lymphoma (NHL) characterized by diffuse or vaguely knotted growth made up of relatively small centrocyte-like cells. Important subgroups consist of larger or blastic cells, and are called polymorph or blastic variations, respectively, of mantle cell lymphomas. These subtypes may be difficult to diagnose correctly and may be misinterpreted either as diffuse large cell lymphoma or leukemic infiltration/lymphoblastic lymphoma.
In addition to morphology, this diagnosis is made with immunohistochemistry (CD5+, CD23-, cyclin D1+) and karyotype t(11;14)(q13;q32) (PRAD1-gene involved/cyclin D1).
The median age of disease debut is relatively high (63 years) and three out of five patients are men. This subgroup constitutes only 6% of all NHL. The disease is usually advanced with frequent involvement of bone marrow, the spleen, and GI tract.
Because of the aggressive clinical profile and relative chemo-resistance, life expectancy is less than for almost all other types of NHL. Median survival with traditional CHOP-based therapy is 3 years, but 20-30% are alive after 5 years. There is also a nodular variant of MCL that may be in stage I/II (5–15% of MCL) and has a less severe disease course than those more diffuse and in stage III/IV.
Chlorambucil or CHOP chemotherapy has long been standard treatment with the goal of prolonging life with a palliative effect, not curative. Promising results have been achieved by combining cyclophosphamide, doxorubicine, vincristine, and dexamethasone with high-dose cytarabine and methotrexate (Hyper-CVAD). It is also now known that the treatment effect for mantle cell lymphoma is improved by adding rituximab to different regimens. It is still not yet known whether newer treatment programs may have a curative potential.
A randomized German study shows that consolidative HDT with SCS after induction therapy gives better disease-free survival than consolidative with interferon-a. Standard treatment for patients under 65 years is induction with maxi-CHOP-rituximab alternating with high-dose cytosar-rituximab (6 cycles together) and thereafter consolidative HDT with SCS.
Patients more than 65 years are treated according to the same guidelines as diffuse large cell B-cell lymphomas or are included in a NLG study with the combination rituximab-bendamustine-lenalidomide.
MCL patients in stage I are considered for curative radiation therapy to 40 Gy to fields similar to follicular lymphomas, confined disease.
Experimental treatment for mantle cell lymphomas
- Patients over 65 years
- Nordic phase I/II study with rituximab-bendamustine-lenalidomide
- Patients under 65 years with poor prognosis
- 6 courses of high-dose cytarabine-rituximab followed by HDT with SCS in responders