Roentgen Diagnosis and Treatment of Persistent Thymus

Abstract

CONTROVERSIAL issues abound in medicine no less than in other scientific endeavors, and this is said without disparagement. In some cases the unquestionable association of cause and effect is convincingly established and needs no further elucidation or defense. Ever since 1614, when Plater reported a sudden death, without apparent cause, in a five-months-old child, in whom necropsy revealed an enlarged thymus as the only abnormality, considerable discussion has beclouded the issue of status thymicolymphaticus, which was first advanced as a definite clinicopathologic entity by Paltauf in 1889. The latter described this condition as due to a decreased resistance of the body to shocks or injuries, dependent on a specific constitutional anomaly, shown anatomically by prominent thymic and lymphatic tissue. This has been generally accepted. However, in 1926, the British Medical Research Council and the Pathological Society of Great Britain and Ireland appointed a joint committee to investigate status lymphaticus. The object was to establish by means of a large series of weights and measurements the standards for age and proportion to body weight of the normal thymus at all ages; also to investigate closely the cause of death in persons dying suddenly from unexplained or seemingly trivial causes, wherein the only apparent abnormality was the presence of a large thymus. The committee determined that, in the normal series up to sixteen years of age, there appears to be little, if any, association between the weight of the thymus and the amount of lymphoid tissue in the various parts of the body, insofar as this amount can be indicated by volumetric measurements of the faucial and lingual tonsils, selected lymph glands from certain sites, Peyer's patches, etc. The few data available show no concomitant general hyperplasia of lymphoid structure in cases with abnormally large thymus. They concluded that in many cases of Graves' disease the thymus was large, due to increase in glandular tissue, yet there was no definite general hyperplasia of lymphoid structures. They also agreed with Hammar and Greenwood, and Woods, that there is no evidence that so-called “status thyrnicolymphaticus” has any existence as a pathologic entity. So, for the sake of agreement, let us acknowledge that there is such a thing as an enlarged thymus, since this committee has recognized its occasional presence, as have roentgenologists, also; certainly, pediatricians have clinically recognized its existence for a long time. Noback has shown that the lobation of the thymus is determined early in fetal life, that the bilobed type of thymus predominates and that its location is most frequently cervicothoracic. The organ is distinctly broad in outline, extending laterally as far as the anterior axillary line in most cases, and is practically never overlapped by fetal lungs.