Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma).
MALT lymphoma, also called
extranodal marginal zone lymphoma of the MALT, arises in a number of epithelial tissues; this most area are the gastric, ocular, bowel, pulmonary and salivary glands.
Patients with localized
extranodal marginal zone lymphoma of the thyroid or other indolent histologies (e.
Findings on pathologic examination were consistent with
extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma).
For our discussion, MZL includes
extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), nodal marginal zone lymphoma, and splenic marginal zone lymphoma, although immunologically splenic marginal zone lymphoma is somewhat different from extranodal or nodal MZL.
10,17,21) Primary cutaneous marginal zone lymphoma, a variant of
extranodal marginal zone lymphoma that is limited to the skin at diagnosis, is a low-grade B-cell lymphoma with a favorable prognosis (5-year survival of 90%-100%).
Pulmonary
extranodal marginal zone lymphoma with massive crystal storing histiocytosis.
Extranodal marginal zone lymphoma of mucosa associated lymphoid tissue (MALT lymphoma) does not typically have a nodular appearance unless the neoplastic cells colonize reactive follicles.
The concept of
extranodal marginal zone lymphoma of MALT type has revolutionized the criteria for the morphologic diagnosis of an extranodal lymphoma, specifically those lymphomas dominated by small lymphocytes.
In addition, some NHLs, such as mycosis fungoides and
extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT), occur predominantly or entirely in extranodal sites.
Although a number of B-cell lymphoproliferative processes (either primary splenic or secondary involvement) were considered in the differential diagnosis, including chronic lymphocytic leukemia/small lymphocytic lymphoma, mantle cell lymphoma, lymphoplasmacytoid lymphoma (immunocytoma), follicular lymphoma,
extranodal marginal zone lymphoma, and hairy cell leukemia, the histologic findings as well as immunophenotypic analysis were felt to be most in keeping with a splenic marginal zone B-cell lymphoma.
