Shima Kannadas1, Rajeevan Kunnaruvath2
BACKGROUND
Extranodal marginal zone lymphomas are rare groups of B cell lymphomas that
arise in mucosa associated lymphoid tissues of various sites. Strong association
with autoimmunity and certain infections are its distinct features. Diagnosis is by
histology with immunophenotyping alongside ruling out other low-grade
lymphomas. In this study we wanted to analyse MALTomas with regard to their
clinical features, relation to autoimmunity, histological and immunohistochemical
profile.
METHODS
This is a descriptive study conducted from 2013 to 2018 at a tertiary care centre
in North Kerala. Study sample included all cases of extranodal lymphomas obtained
retrospectively from 2013 to 2017 and prospectively from 2017 to 2018. Blocks
of all specimens were cut and stained with haematoxylin and eosin (H & E) and
immunohistochemical markers.
RESULTS
Out of the 15 cases we analysed, the most common sites of involvement were
gastrointestinal tract (40 %) followed by thyroid (27 %). Thyroid, which is a rarer
site for MALT lymphoma, is detected as one of the frequent sites in this study. In
our study, stomach was one of the less common site affected which is in contrast
to other studies. Associated autoimmune disorder was detected in 20 % of cases.
46 % of cases show features of transformation to high grade lymphoma.
CONCLUSIONS
This study analysed the features of MALT lymphomas in different sites and found
a strong association with autoimmune disorders. Rarer sites like thyroid were
found to be more frequently involved and common sites like stomach was detected
in only small percentage of cases. Although most cases are indolent low-grade
lymphomas, possibility of transformation to a high-grade B cell lymphoma should
always be considered when dealing with these cases. Utility of
immunohistochemistry in ruling out other small cell lymphomas is also well
demonstrated in this study.
