[Incidence of lymphoproliferative diseases in Northern Italy]

In the last 6 years we have observed an increasing number of cases of lymphoma, extranodal cases being the majority over nodal ones. This fact induced us to investigate the incidence of NHL and HD in the population served by the Lecco Hospital, Department of Pathology, as well as the temporal trend from 1990 to 1995. MATERIALS AND METHODS AND DATA: All hospitals and dispensaries located in the surrounding areas of Lecco including the district of Menaggio and Morbegno are dependent on the Department of Pathology of Lecco Hospital. In fact, the surgical pathology of this area with its 272144 inhabitants converges in our department. We investigated the incidence of nodal and extranodal lymphomas in this population in the period between january 1990 and december 1995 while isolating the number of new cases reported in our files. The incidence per age, population over three-years period has been epressed as the number of cases per million population per year (cases per pmp/y).

285 patients aged 20 to 90 years old (mean 62.5) were selected (51% males, 49% females): they presented 141 nodal lymphomas (36 HD and 105 NHL) and 144 extranodal lymphomas of which 57 primary gastric lesions (22 males and 35 females, mean-age 63.5 in the male group (range 38-85) and 59.0 in the female group (range 31-91)). In nodal as in extranodal lymphomas the diffuse large B-cell lymphomas were the most frequent entity diagnosed, furthermore we noted an increase of incidence in all age groups in the last six years for NHL, mostly NHL HG, in contrast to decrease for HD. About gastric lymphomas, 2/3 were diffuse large B-cell lymphoma with or without low grade component, while the remaining were low grade B-cell lymphoma and only three cases were gastric peripheral T-cell lymphoma. Gastric lymphomas show a higher incidence than in other countries.

These results show an increase of the incidence of non-Hodgkin lymphomas, mainly of high grade, during six years and in all age groups. On the contrary we observe a tendency in reduction for Hodgkin Disease. Primary gastric lymphomas show a greater increase and their incidence has been estimated in 17.5 cases per 100,000 per 5 years.