Malignant lymphoma in Jordan: A retrospective analysis of 347 cases according to the World Health Organization classification

BACKGROUND: Most studies describing the subtypes of lymphoma in Jordan were carried out in the 1980s at a time when immunohistochemical facilities were unavailable. Using a database established after immunohistochemical studies were introduced, we determined the frequency of the various types of nodal and extranodal lymphomas in the adult and paediatric Jordanian population. We also assessed the incidence of bone marrow involvement at the initial presentation for each lymphoma type. METHODS: A retrospective analysis of the histopathological subtypes of various lymphomas was conducted on all primary lymphoma cases diagnosed during a 3-year period between January 2001 and December 2003. RESULTS: Of 347 patients included in the study, 78.4% had non-Hodgkin's lymphoma (NHL) and 21.6% had Hodgkin's lymphoma (HL). In the NHL group, diffuse large B-cell lymphoma was the most common (28.2%) followed by follicular lymphoma (15.6%). In the HL group, the nodular sclerosis variant was the most frequent (7.8%) followed by the mixed cellularity type (5.5%). Of all the lymphoma cases, the highest incidence of marrow involvement was seen in patients with lymphoplasmacytic lymphoma. Forty-nine patients were children (age <15 years) in whom Burkitt's lymphoma (15 cases) and HL (14 cases) were the commonest subtypes. One-hundred six patients with primary extranodal lymphomas (ENL) accounted for 30.5% of all lymphomas. CONCLUSIONS: There is a higher incidence of NHL in Jordan compared with other series in the Middle East, Among the various lymphomas, diffuse large B-cell lymphoma is the most commonly encountered lymphoma in adults. Burkitt's lymphoma and Hodgkin's disease are the most frequent childhood lymphomas, followed closely by lymphoblastic lymphoma.