In the use of the so-called antithyroid substances, most noted propylthiouracil, the production of thyroid hormone is decreased. These compounds cause an enlargement and marked hyperplasia of the thyroid gland, with corresponding depression of metabolism and a decrease in the formation of thyroid hormones. The iodine content of the thyroid decreases, although the ability of the gland to trap iodine is not destroyed.
In considering the various diseases of the thyroid, for sake of brevity, we will deal with:
1. Congenital Anomalies: These are of the aberrant type of thyroid and thyroglossal duct cysts, sinuses and fistulae.
a. Acute form – suppurative and non-suppurative.
b. Chronic – which comprises Simple; Reidels Struma; Hashimotos Disease; Specific infections (actinomycosis, syphilis and tuberculosis).
3. Iodine Deficiency Goiter: Subiodic goiter; Simple goiter; colloid goiter – pubertal, Adolescent Gestational; Menopausal; Endemic; Sporadic.
4. Hypothyroidism” Adult myxedema; Cretinism; Juvenile myxedema.
5. Non-Toxic Nodular Goiter, arising from pre – existing subiodic goiter, from pre – existing Graves disease, and fetal adenoma.
a. Graves Disease.
b. Plumbers Disease (toxic adenoma)
(1) Under the congenital anomalies or aberrant type of thyroids, we remember from the embryonic development of the thyroid, the path of its descent into its final location in the neck. Any variations which may occur during its descent will give rise to these aberrant thyroid itself. These are subject to the same cell changes which occur in the thyroid gland per se.
The thyroglossal duct cysts, it must be recalled, will be differentiated by the fact that they are in the midline. They may be ruptured and form a fistula which in turn may drain from time to time. They may a drain into the mouth if the duct cyst is above the hyoid bone.
In my experience there have been times when we have had a normal thyroid gland and have had a hyperactive aberrant gland located in some position in the neck which will give rise to thyroid – toxic symptoms. In these case we remove the aberrant gland.
The thyroglossal duct cysts usually are noted in the early years of life and do not harm unless their size produces a poor cosmetic effect and are removed for this reason; or due to some infection of the tract they will rupture and form a fistulous tract, which must be excised.
(2) A Thyroiditis – The acute form of thyroiditis will occur following some other form of infection through the body, such as pneumonia, bronchitis, diseased tonsils, or any other form of infection. As a rule, these cases will subside under treatment with the antibiotics or sulphonamids within 10 days to 3 weeks. Occasionally when there is suppuration, we will find pressure symptoms, high temperature; and of course radical incision and drainage of the affected site is surgically indicated.
B. In Chronic Thyroiditis, we must consider such conditions as Reidels Struma, Hashimotos Disease and the specific infections such as actinomycosis, syphilis and tuberculosis.
The Reidels Struma is known also as the Woody type of thyroiditis or the Ligneous type of goiter. In these cases, there is a dense struma throughout the gland which on section cuts almost like cartilage. Reidels struma does not occur too frequently (approximately 2 percent of all thyroidectomies have been performed upon Reidels struma). It is more common in women than in men. The clinical symptoms and signs of Reidels struma depend upon the presence of the goiter, the alterations of thyroid function, and the disturbance due to pressure.