POSTMORTEM FINDINGS IN THE NIJMEGEN BREAKAGE SYNDROME

Autopsy findings for two patients with the Nijmegen breakage syndrome (NBS) are presented. This syndrome has the same type of immunologic an d cytogenetic abnormalities as ataxia telangiectasia (AT). In NBS, how ever, microcephaly is found and progressive cerebellar ataxia and ocul ocutaneous telangiectasia ale lacking. The demonstrate a clear neuropa thologic difference between these two syndromes, as the diffuse cortic al cerebellar degeneration characteristic of AT was absent in NBS. In the thymus the histologic picture was suggestive of simple simple dysp lasia. Lymphoid tissues were slightly atrophic but otherwise structura lly normal. In one of the two presented cases an extranodal diffuse la rge cell malignant non-Hodgkin lymphoma of B cell immunoblastic type w as found in Waldeyer's ring, in the small and large intestines, and in the brain, whose sequelae had caused death. Six of the 19 patients kn own with certainty to have this syndrome have developed lymphoid malig nancy, which indicates that these patients are prone to develop malign ancies.