A STUDY OF THE MORPHOLOGICAL PATTERNS OF EXTRANODAL NON-HODGKIN LYMPHOMA IN PAKISTANI AND SAUDI POPULATIONS

Background: The incidence of extranodal non-Hodgkin lymphoma (EN – NHL) is increasing particularly among the populations of South Asia and Middle East. On the whole 25 – 40% of NHL arise in the sites other than lymph nodes.Objectives: This study was designed to assess the pathological patterns and the prevalence of EN-NHL in Pakistan and in Saudi Arabia.Methods: A total of 106 and 42 cases, from one centre in Pakistan and Saudi Arabia respectively, were included during a five year period (1998 – 2003) with a detailed account of their demographic and clinical characteristics.Results: We observed that most of the Pakistani and Saudi patients presented in the 5th – 7th deca-des with the mean age being 43.2 and 46 years and a male to female ratio of 1.07 : 1 and 1.7 : 1 res-pectively. Apart from a diverse pattern observed, diffuse large B cell lymphoma (57.5% and 63.4%) followed by MALT lymphoma (28.3% and 26.8%) were the commonest morphological subtypes of EN – NHL in both genders belonging to Pakistan and Saudi Arabia respectively. The tumours were found to be widespread, however, a predominant gastrointestinal tract (45% and 41.3%), in particular, gastric involvement was seen in (20.8% and 19.5%) Pakistani and Saudi patients respecti-vely. However, predominant orbital involvement was seen exclusively in the latter.Conclusion: EN – NHL is an emerging malignancy in Pakistan and Saudi Arabia. Apart from a slight variation, no significant divergence was observed in the histological patterns of the EN – NHL in both geographical areas.