Application of the World Health Organization classification in the study of nonhodgkin's lymphoma in western Saudi Arabia

ABSTRACT

The aim of this study was to analyze the clinical and histopathologic distribution of various types of non-Hodgkin's lymphoma [NHL] at King Abdulaziz University Hospital-Jeddah, using the World Health Organization classification [WHO] of lymphoid neoplasms and to compare our results with those reported in the literature. A hundred and nine patients with malignant NHL diagnosed over a 10-year period from January 1994 through 2004 were retrospectively studied clinically and histopathologically. They were classified using the WHO classification, and recorded in a structured form. Of the 109 patients with NHL, 42 [47.2%] were Saudi and 67 [75.3%] were Non-Saudi, with male to female ratio of 1.721. The mean age of the patients was 48 years, age range [12-93 years]. Immunologically, the percentage of NHL with B-cell and T-cell phenotype were 88 [80.7%] and 21 [19.3%] respectively. Diffuse large B-cell lymphoma was the most frequent histopathological diagnosis 50 [45.9%] followed by follicular lymphoma 11 [10.1%] and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma was the third most common histopathological subtype of non-Hodgkin's lymphoma 8 [7.3%]. Lymphoblastic T-cell was the predominant subtype among the T-cell non-Hodgkin's lymphoma 10 [9.2%]. The proportion of primary extranodal NHL was 20[18.3%] with the gastrointestinal tract being the commonest site in 12 of the cases. Prevalence of advanced clinical stages of the disease 58 [53.2%] were recognized. B symptoms were reported from 68[62.4%] of nodal, 11[10.1%] of extranodal NHL patients. The distribution of various types of Non-Hodgkin's lymphoma showed clinical and histopathological similarities and differences when compared using the WHO classifications with other Non-Hodgkin's lymphoma series from the region, Asian countries or the West. The age group [40-60] years seen commonly with nodal NHL while [50-80] years [older age group] present with extranodal NHL. Diffuse large B cell lymphoma represents the most common histologic subtype followed by follicular lymphoma. In contrast, T-lymphoblastic lymphoma was relatively more frequent compared with that of Western populations. Extranodal marginal zone B-cell lymphoma [MALT type] of the gastrointestinal tract accounted for majority of the primary extranodal lymphoma