Familial Lymphomas A review of the literature with report of cases in Jerusalem.

Non-Hodgkin's lymphoma Although non-Hodgkin's lymphoma (NHL) is a common disorder, there are relatively few reports occurring in family groups. Extensive review of the literature by Ladish et al. in 1978(1) revealed 38 multiple-case families with NHL, most of whom were sibpairs, either sibs alone (6.3%) or sibs plus other relatives (13%), including a pair of monozygotic twins(2). The mean age of diagnosis in these cases was 23.5 years compared with 42.3 years for the general population with NHL. About half of the familial cases were extranodal (44 cases), primarily involving the gastro-intestinal tract in 26 cases, with the distal small bowel and cecum being most frequently affected. No histologic type was predominant in the affected families(3). As described for Hodgkin's disease (HD)(4,5) increased incidence with small family size has been observed for NHL; however, no change in risk has been seen with increasing family size(6).