ABSTRACT
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. This study was designed to assess the pathological patterns and the prevalence ofEN-NHL in Pakistan and in Saudi Arabia. A total 0/106 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. We observed that most of the Pakistani and Saudi patients presented in the 5[th] - 7[th] decades with the mean age being 43.2 and 46 years and a male to female ratio 0/1.07: i and 1.7: i respectively. 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 respectively. However, predominant orbital involvement was seen exclusively in the latter. 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