Thyroiditis

THYROIDITIS (thyreoiditis), inflammation of the thyroid gland, as distinguished from strumitis (strumitis)—inflammation of a gland that has already degenerated into a goiter. T. rarely arises from direct introduction of infection into the gland tissue through accidental injury or puncture; usually, infection develops hematogenously in various diseases. Thyroiditis has been observed in typhoid, post-pneumonic, influenza, scarlet fever, smallpox, mumps, whooping cough, acute articular rheumatism, acute osteomyelitis, puerperal fever, sore throat, malaria, gonorrhea, etc. Sometimes T. occurs seemingly independently, and then one speaks of 'primary' T., of cryptogenic infection. American authors attribute great importance in the etiology of thyroiditis to catarrhs of the upper respiratory tract, tonsillitis, and carious teeth. Pathoanatomical changes in the thyroid gland are very diverse. In some cases, acute inflammatory phenomena are observed with significant small-cell infiltration, enhanced desquamation of the follicular epithelium, new formation of blood vessels, and development of interlobular connective tissue. These phenomena either regress, leaving in the gland the usual traces of acute parenchymatous inflammation, or the process passes into a chronic form or into suppuration. Abscesses are observed either single, gradually destroying the gland and involving surrounding tissues and organs in the process, or one or another lobe or the entire gland appears permeated with small abscesses. In chronic inflammation of the gland, a general decrease in the weight of the gland is noted, liquefaction of its colloid and its disappearance, enhanced development of connective tissue, and a sharply expressed focal or diffuse small-cell infiltration of the gland parenchyma. With particularly virulent infection, T. may take on a hemorrhagic character. In chronic T., in a number of cases, due to irritation of still unchanged parenchyma, thyrotoxic phenomena are observed. In such cases, histologically, there is undoubtedly hyperplasia of the glandular tissue around the focus of small-cell infiltration (Clute, Lahey). On the other hand, as a result of chronic T., myxedema very often develops. The most pronounced destruction of the thyroid gland parenchyma is observed in the so-called Riedel's goiter, which histologically represents T. with the most fully expressed replacement of thyroid tissue by round-cell infiltration. The inflammatory infiltration and growth of connective tissue go so far that the gland tissue may completely disappear, therefore Simmonds named this form cirrhosis of the thyroid gland. Particularly characteristic for Riedel's goiter is the cartilaginous density of the somewhat enlarged thyroid gland. Hence the name eisenharte Struma of German authors and 'woody goiter' of the French {thyreoidite ligneuse}. Macroscopically, in the gland tissue, either separate very dense nodular nodes are determined or the entire gland is somewhat enlarged, nodular, of cartilaginous consistency, so that it is not difficult to confuse with a malignant neoplasm. Not always, however, even histological research can give an exhaustive answer, since among the accumulation of lymphoid elements, a large number of large plasma cells, characteristic of a tumor, are often noted, and in some cases only further clinical observation decided whether this was a malignant tumor or chronic T. Clinical picture. T. is distinguished as acute and chronic. The degree of expression of inflammatory phenomena in the thyroid gland is very diverse, and depending on this, the clinical picture is also diverse. Thus, in a number of cases, acute T. proceeds according to the type of 'thyreoiditis simplex' and after a slight painful swelling of the thyroid gland, with painful sensations on swallowing, with a slight elevation of temperature (37°-38°), it disappears without a trace or turns into chronic T., sometimes from the very first days of the disease one has to deal with a rapidly developing process leading to suppuration—thyreoiditis purulenta. Thyreoiditis simplex is often encountered. Lahey observed 42 cases over 5 years and considers that this disease occurs much more frequently, since most of these patients are treated on an outpatient basis, and the often observed enlargement of the thyroid gland is taken for a diffuse colloidal goiter. One of the early symptoms is considered to be painful sensations when swallowing solid food. Sometimes slight thyrotoxic phenomena with an increase in basal metabolism up to +15%, rarely up to +30%, are noted. Painful sensations last 8-10 days and under the influence of rest and heat on the area of the gland disappear without a trace. Myxedema is as a rule not observed. In rare cases, the process takes on the character of chronic T., even more rarely a slowly resolving abscess develops. Purulent T.—a significantly rarer disease, Lahey and Klute observed 5 cases over five years; periodic reports of individual (1-2) cases appear in the literature. The disease immediately takes a severe form. High temperature (up to 40°), pain on swallowing, extreme tenderness on touching the thyroid gland, difficulty in breathing. The most convenient position for the patient—bending the chin to the anterior chest wall to relax the muscles lying in front of the thyroid gland. The inflammatory process in the gland quickly involves surrounding tissues, redness of the skin, fluctuation appear. If the abscess is not recognized in time, it may rupture either into the area of the anterior surface of the neck or into adjacent internal organs—into the esophagus, into the trachea, into the mediastinum. In the latter case, the outcome is death. In sepsis, an abscess may form secondarily in the thyroid gland, and it is characteristic that such an abscess can reach considerable size without clinical symptoms. Treatment—wide incision with dissection of the anterior neck muscles and drainage of the abscess. With multiple abscesses in one of the lobes or with suppuration in a node, resection of the lobe or enucleation of the affected node is indicated. The prognosis for primary purulent thyroiditis is good if an incision is made in time and the abscess cavity is well drained; in secondary, metastatic cases, in sepsis—the prognosis depends on the success of the fight against sepsis in general. Chronic T. occurs much more frequently than purulent T. Just as the pathoanatomical picture of chronic T. is diverse, so is the clinical picture. Thus, Lahey and Klute divide 84 patients with chronic T. into the following subgroups: chronic thyroiditis—43 patients, Riedel's goiter—22 patients, thyroiditis with thyrotoxicosis—15 patients, tuberculous thyroiditis—2 patients, syphilitic thyroiditis—2 patients. In simple chronic T., in the enlarged thyroid gland, with slight painful sensations, either separate dense nodular nodes develop or the entire gland appears diffusely enlarged, as in colloidal goiter. Before the operation, one thinks of a malignant or ordinary nodular goiter, for which the operation is performed, most often resection or enucleation of nodes. Often (in 1/8 of cases) in operated patients, myxedema develops, therefore it is indicated to perform the operation only in the presence of compression phenomena and difficult breathing, leaving as much macroscopically unchanged tissue as possible, if clinically before and during the operation it is possible to establish that these nodes are not malignant. As indicated above, errors are possible and quite frequent. The Riedelian form of goiter is rather rare. If Lahey and Klute observed 22 cases, European surgeons report (Mysch, Levit) on individual cases. The main complaint in this form—difficulty in breathing due to compression of the trachea. Until the process is limited to the thyroid gland, it is mobile during swallowing movements; later, the process passes to the surrounding tissues, sometimes spreading very far—to the base of the skull (Tailhefer) and into the anterior mediastinum (Meyer). In 7/3 of cases after the operation for Riedel's goiter, myxedema develops, therefore, just as in ordinary chronic T., one should leave as much gland tissue as possible. The simplest operation—excision of the isthmus to free the trachea. The most interesting from the clinical side is T. with phenomena of thyroid gland dysfunction. In this form, thyrotoxic phenomena are observed, sometimes so sharply expressed that such patients are treated as patients with primary Basedow's disease or with thyrotoxic adenomas, with high figures of basal metabolism and other symptoms. During the operation on them, the unusual density of the resected thyroid gland tissue strikes the eye. In such cases, subtotal or total resections or hemithyroidectomies, enucleations, and other types of operations used in Basedow's disease were performed with good immediate results. Subsequently, in 7/3 of cases, myxedema develops, with which, however, one can fight by prescribing thyroidin and which patients tolerate more easily than severe Basedow's disease.—Syphilitic lesion of the thyroid gland is observed in 2 forms: 1) painless soft swelling in the early stage, 2) dense nodular swelling—gumma. Often—compression of the trachea. Easily confused with a malignant neoplasm. Combinations with syphilitic tonsillitis and pharyngitis, positive RW are not uncommon.

Specific treatment gives good results. Tubercular T. is rarely encountered. Clinically it resembles nodular goiter. Before caseous degeneration and the appearance of characteristic abscesses, it is difficult to recognize. Treatment consists of resection within healthy tissues.