THE PATHOLOGICAL ANATOMY 287 



plasia, especially those associated with adrenal insufficiency, this lymphoid 

 tissue may undergo hyper plasia as part of the general lymphoid hyper- 

 plasia throughout the body, even to the extent of forming large germinal 

 centers. There is no basis at present for considering this inflammatory. 

 True inflammatory reactions are rare. They are never primary. Many 

 of the so-called forms of acute thyroiditis are scarcely more than active 

 hyperemias or cloudy swellings. These conditions are not infrequently 

 seen in acute infectious diseases, in food intoxication, drug rashes, in- 

 testinal exanthemas and following extensive skin burns. A thyroiditis 

 due to the administration of iodin has been described. lodin does not cause 

 thyroiditis. The administration of large amounts of. iodin to an indi- 

 vidual with actively hyperplastic goiter may cause the gland to become 

 very firm, even enlarged, and quite painful, due to stretching of the 

 capsule. The thyroiditis simplex described by some authors has been 

 referred to under cloudy swelling or parenchymatous degeneration. Sup- 

 purative thyroiditis may occur in the course of puerperal infections, ulcera- 

 tive endocarditis, scarlet fever, typhoid fever, influenza, pneumonia, 

 tonsillitis, and may also occur as a direct extension from adjacent struc- 

 tures. It is more frequently seen in thyroids that have undergone goiter- 

 ous enlargement or which contain benign tumors. Thyroid tissue with 

 impaired vitality forms excellent foci for the lodgment and growth of 

 pyogenic organisms. Injuries, as in the old iron and iodin injections, 

 were frequently followed by necrosis and subsequent abscess formation. 

 In generalized tuberculosis the thyroid is commonly involved. There is 

 no recorded instance of primary tuberculosis. Gummata are being re- 

 ported with increasing frequency. Bauer, Clairmont, Davis, Dunger, 

 Ewald, C., Hedinger, Melandri and Legg, Pollag, de Quervain, Eoger and 

 Gamier, Schutz. . 



Tumors 



The two distinctive groups of thyroid epithelial tumors are the adeno- 

 mas and carcinomas. Bircher, H., Langhars (a) (&), Marine (a). 



Adenoma. This group includes a very vague and indefinite series 

 of tissue proliferations ranging from the well defined, circumscribed and 

 encapsulated masses of glandular tissue to the diffuse, uniform hyper- 

 plasia of simple goiter. Anatomical separation of those groups which 

 might properly be called adenomas, from those which should be grouped 

 with simple hyperplasias, is not possible. It is possible by utilizing the 

 biological test with iodin to make a partial separation. Such tests show 

 that the more differentiated the tissue the more nearly it reacts with 

 iodin like normal thyroid. Even the more undifferentiated the so- 

 called fetal adenomas have some power to react with iodin and 

 one must conclude that while anatomically and for convenience these 



