Non-Hodgkin lymphoma in Jordan. Types and patterns of 111 cases classified according to the WHO classification of hematological malignancies.

OBJECTIVE Non-Hodgkin lymphoma (NHL) is one of the most frequent malignancies in Jordan. The aims of this study are: 1. To classify NHL cases in Jordan, using the new World Health Organization (WHO) classification system, 2. To identify the most common types of NHL in Jordan, and 3. To compare lymphoma types and patterns in Jordan with those in surrounding countries and the West. METHODS We studied all NHL cases, diagnosed during 1996 through to 1999 inclusive, at 2 major medical centers in Jordan, in order to identify their main types and patterns. One hundred and eleven cases of confirmed NHLs were reexamined and immunophenotyped in the year 2000, at the Department of Pathology, Jordan University of Science and Technology, Irbid, Jordan, using an immunohistochemical panel of antibodies, including CD3, CD15, CD20, CD30, CD43, CD45 and CD45RO. Confirmed NHL cases were reclassified according to the recently proposed WHO system of Hematological Malignancies. RESULTS The median age of NHL cases was 44-years (range 2-85). The vast majority of cases were of B-cell phenotype; only 14% of the cases were T-cell lymphomas. Most of the cases were of the aggressive intermediate to high-grade large cell type. Diffuse large B-cell lymphoma (DLBCL) comprised 53% of NHLs and 62% of B-cell NHLs. Indolent lymphomas were uncommon, comprising 14% of all NHL cases. Twenty-nine cases were seen among patients less than 20-years. Burkitt lymphoma represented the largest group (55%) of the childhood NHLs followed by diffuse large cell and lymphoblastic types. CONCLUSION Indolent lymphomas are rare in Jordan and account for less than 15% of all NHLs. Aggressive lymphomas; on the other hand, account for the majority of NHLs in Jordan. Burkitt lymphoma affected children less than 10-years of age with a median of 4.5-years. These observations indicate that NHLs in Jordan have different type distribution and patterns from those seen in the West.