Clinico-pathological study of thymic dysplasia.

In a recent necropsy study of a thousand cases in which adequate amounts of thymus gland were available, Berry (1968) found a large number of abnormalities.Most of these were related to the lymphocyte population and in some cases apparently resulted from the exhibition of cytotoxic drugs or steroid hormones.In 17 cases epithelial abnor- malities were found, these glands showing lympho- cyte depletion associated with absence of, or reduction in, the number of Hassal's corpuscles to less than 5% of the normal numbers for the age.The normal data were derived from Boyd (1932).In all 14 ofthese 17 cases in which adequate material remained for examination, other abnormalities of lymphoid organs were found.The clinical histories of these 17 have been reviewed, and in 14 where adequate data were available, a clinico-pathological correlation was attempted.The clinical and pathological findings are summarized in Tables I and II: photomicrographs of classical thymic, lymph node, and appendiceal abnormalities are shown in Fig. 1, 2, and 3. Clinical FeaturesIn 12 of the 17 patients the clinical history and findings were similar, the salient features being diar- rhoea, failure to thrive, and recurrent infections (Cases 1-4, 6-9, 11-14).All but one (Case 15-congenital rubella) had birth- weights greater than 2721 g. (6 lb.).Most did well initially, the exceptions being those patients with the rubella syndrome who never thrived (Cases 15-17).At death, all but 2 (Cases 5 and 10) had weights below the 3rd centile; these 2 were atypical in other respects and are described separately.The age of onset of symptoms was between birth and 8 months.An apparent relation between age at onset and age at death was found, with a less rapid course in those in whom the onset of symptoms was late.A history of similarly affected sibs (Cases 2, 7, and 13) and cousin (Case 7) was found in 3 cases.Because of this history these patients had been investigated before the onset of symptoms.Of the 17 patients, 12 were male.