13.          Non-Hodgkin’s Lymphoma, extranodal primaries

13.1        Mucosa-associated lymphoid tissue (MALT)/marginal zone lymphomas (MALT/MZ NHL)

General considerations

Around 8% of all NHL arise from MALT which is provoked by pre-existing inflammatory responses. These lymphomas arise at numerous extranodal sites with gastric MALT lymphoma being the most common and best studied. Gastric MALT lymphomas are considered to be a consequence of a Helicobacter pylori infection and H. pylori eradication is the initial treatment of choice for localized disease. It can produce histologic regression of the lymphoma which can be maintained for years. For those not responding as well as for more advanced gastric MALT lymphomas and those at non-gastric sites treatment may include radiotherapy, chemotherapy, surgery, or a combination thereof. Single-agent therapy (e.g. chlorambucil or cyclophosphamide** or cladribine*) is usually, while combination chemotherapy (e.g. with CHOP) may have a role in the treatment of patients with a large tumor mass, or those with a significant proportion of large cells.

Literature:

CAVALLI et al, Hematology (Am. Soc. Hematol. Educ. Program) (2001): 241–258 (for review)

* JAGER et al, J. Clin. Oncol. 20 (2002): 3872-3877

MAES and De WOLF-PEETERS, Histopathology 40 (2002): 117 – 126 (review)

WOTHERSPOON et al, Curr. Opin. Hematol. 9 (2002): 50 – 55 (review)

** ZINZANI et al, J. Clin. Oncol. 17 (1999):  1254 – 1258 (non-gastrointestinal localization)