THYREOPLASIA CONGENITA (Athyrensis Concentra, Infantile Mystedetna. Myxeedernatous Idiocy, Sporadic Cretiniorrd This affection was first observed and described about thirty years ago in England and France, later especially in Germany, and its existence is now demonstrated in all civilized countries. Nevertheless, a complete understanding of it is still lacking, and it presents many difficulties to the specialist, especially in the first year of life, leading to confusion with other and apparently similar diseases.
The cause of congenital absence of the thyroid is unknown. The autopsy findings have yielded no information on the subject except the fact that the organ was missing. The epithelial corpuscles which, in the human being, are not embedded in the gland have always been found intact whenever they' were looked for.
When the mother is healthy, an infant with congenital absence of the thyroid shows nothing abnormal at the time of birth, the thyroid secretion transfused through the maternal blood being sufficient for some time to prevent manifestations of absent function (Kocher). It has often been asserted, but never proved, that the secretion is imparted to the mother's milk.
The first symptoms occur in the artificially fed after a few weeks, sometimes as late as after three or four months. They consist in a gela tinous, doughy swelling of the subcutaneous connective tissue, defective growth in length, swelling of the mucous membranes, and hypertrophy of the tonsils. At this early period physical and mental apathy have become apparent and further symptoms rapidly appear.
The cranium rapidly grows, the fontanels remain wide open, and the head sits close upon the thorax owing to shortness of the neck. The small, broad, blunt saddle nose, the puffy palpebrie and narrow lid fis sures, the sometimes prominent eheek-bones, the ugly large mouth, with its coarse tongue, frequently' permanently protruding exceedingly, im part to the bloated face a repugnant, animal-like expression. Forehead, cheeks, probosciform lips, and submental region are distended. The ears are often unshapely and thick. The outlines of the body and extrem
ities are indistinct, because modelling through the skeleton cannot take effect, owing to the spongy, bloated soft parts. Very large masses of gelatinous consistency are found in the submental region, at the base of the neck, in the supraelavicular fossx, over the shoulder-blades and acetabula. The extremities become roller-shaped, the fingers and toes are small and clumsy. The abdomen is considerably distended owing to continuous constipation, and there is always a large umbilical hernia, generally- without intestinal contents or easily' reducible (Fig. 121). The hair, (Wen when dense at birth, becomes defective, especially above the temples. Lanugo hair remains for y-ears at the forehead, shoulders and back. The hairs themselves are very dry, hirsute and brittle and hang wildly around the strikingly thick skull. The latter is usually- dolicho cephalous, too large in comparison to the size of the body, never micro brachycephalous as in mongoloid idiocy.
The large fontanel, which is wide open, closes at a very late period, sometimes as late as in the thirtieth or fortieth year. The frontal fon tanels are sometimes similarly affected. The tubular bones, always rather selcrosed, show a complete absence of proliferation of the epi physcous cartilages; all tissues participating in the formation of the skeleton, more particularly the bone marrow which often exhibits true atrophy, are uniformly affected by the arrest of development. Here we have to deal with insufficient funetion of the enchondral and periosteal zones of ossification with minimal bone formation through the osseous marrow and diminished osseous metabolism. Langhans and Dieterle found a transverse osseous lamella closing the diaphysis toward the epithelial nuclei, Steinlin made the same observation in thyroidecto mized als, and I have been able to demonstrate the same in all radio grams as a sharp, black line. The epithelial nuclei will either not develop at all or only at a very late period, while the cartila ginous epiphyses will re main unossified until the most advanced age.