Extranodal localizations of lymphoma. Clinico-epidemiologic study of 353 cases

The Authors have carried out a retrospective study on 353 cases of lymphoma, of which 252 of non-Hodgkin lymphoma (NHL) and 101 cases of Hodgkin's disease (HD), during a 17 year period, i.e. from 1982 to 1999, with the purpose of evaluating the frequency of primitive and secondary extra-nodal localizations and assess their influence on the percentage of survival. A highly significant statistical difference was observed comparing patients with nodal LNH and those with a primitive extra-nodal localization of the disease. In HD extra-nodal localizations were observed at the time of diagnosis in 13% of the cases studied, in which however in the great majority of patients presentation was associated with generalized disease and was therefore the consequence of local spread from near-by lymphoid sites. However, primitive localizations were surely observed and carefully documented. In our patients they were detected in the intestine, in the skin and in the mammary gland. In 253 patients with NHL, 123 sites of extranodal localizations were found (50%) and were observed in the skeletal system, in the skin and in the orbital cavity. The Authors underline the need to improve our knowledge on the structures and mechanisms of spread of the mucosal associated lymphoid tissue in order to better understand the clinical aspects and the necessary therapeutic approach in cases of extranodal and especially MALT lymphomas.