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The principles and practice of modern surgery

Chapter 360: THE THYMUS.
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The volume presents a comprehensive, practical survey of surgical science and practice, beginning with surgical pathology and common infections and proceeding through principles and methods—anesthesia, asepsis, diagnostics, wound management—and detailed treatments of injuries, fractures, dislocations, tumors, and the surgical diseases of tissues and organ systems. It treats regional and specialty procedures for head, spine, chest, limbs and more, and addresses operative technique, preoperative preparation, and postoperative care. Numerous illustrations and clinical examples accompany discussions of etiology, repair, and complications to guide students and practicing surgeons in sound principles and contemporary operative management.

[49] This may afford an explanation of the unsatisfactory character of artificial foods, as well as of cows’ milk, since, unlike the babe, the calf is born with a functionating thyroid. Cows’ milk does not contain in this respect that which is found in human milk, all of which may afford a reason for adding minute amounts of thyroid extract for a short time to artificial foods for children.

That the thyroid normally produces substances of vital import in the human economy is shown both by the bad effects of their overproduction, as in tetany and certain spasmodic affections, with final clonic rigidity, and in thyroidism or the hyperthyroidism of Graves’ disease or exophthalmic goitre, with its tachycardia, mental depression, and numerous other symptoms, and by those of its underactivity, as in myxedema, cretinism, cachexia strumipriva, and certain of the toxemic neuroses.

The relations between the thyroid and the genital organs, especially in the female, are in many instances pronounced. Menstrual suppression and pregnancy are often followed by thyroidal enlargement, and nearly every woman having a goitre notes its temporary enlargement with each menstrual epoch, and its permanent enlargement with each succeeding pregnancy. The most specific constituent of the thyroglobulin, which is supposed to be the substance formed within the thyroid, is iodine, which is present in variable amounts.

In general it may be said of the thyroid: (1) That it secretes some material requisite for normal nutrition; (2) that it has much to do with the assimilation of oxygen by the tissues as well as with phosphorus metabolism; (3) that its peculiar secretion has a marked effect in lowering blood pressure and quickening the pulse, in the former respect being the direct antagonist of adrenalin.

The parathyroids have only recently assumed importance either in surgery or pathology. Their existence as separate structures with an identity of their own was first demonstrated by Sanström in 1860. Up to his time they had been assumed to be small accessory thyroids. In 1884 they were described by Horsley. Since that time they have been an object of the greatest interest to experimenters. They are of different character from the thyroid proper. Nevertheless the two are not absolutely independent of each other, for removal of either one causes changes in the other; the symptoms caused by removal of the parathyroids, especially, including tremors and various nervous symptoms, of which tachycardia and sometimes exophthalmos are the most prominent. Experimental animals will usually survive removal of the thyroid alone, but to take away all four of the parathyroids is almost invariably fatal. Anatomically they consist of two pairs of small bodies, with an average diameter of ¹⁄₂₅ inch, having color and texture much like the thyroid in gross appearance, but containing epithelioid cells, lying in man in close relation to the lateral lobes of the thyroid, behind them and to their inner sides. In minute structure they resemble that of the pituitary body. Their relatively trifling size and deep position in man have caused them to be neglected in pathology, and to be seldom recognized during operations or except by a careful dissection made for the purpose. The present trend of opinion, especially among the experimenters, ascribes to them an important role in the production of exophthalmic goitre, it being made to appear that by some neglect of duty their function of indirectly regulating the heart and controlling the sympathetic system is not properly performed.

CONGENITAL AFFECTIONS OF THE THYROID.

Congenital affections of the thyroid may assume the type either of defect or of absence of the organ, or an hypertrophy which may involve one side or both. Presumably when the thyroid is lacking its function is to some extent assumed by the thymus and perhaps by other portions of the body.

Anatomical alterations are met in the so-called supernumerary or accessory thyroids, which may be due to separate development of one of the original lobules, or they may arise independently. These vary in size, location, and importance. They may be seen as high as the base of the tongue or as low as the upper end of the sternum or behind it. Tissue of this kind has been seen in the body of the hyoid bone. These accessory masses are subject to the same type of affections as those which involve the principal thyroid, and thus tumors may develop in the anterior region of the neck, which may cause some perplexity.

An extraordinary feature of thyroidal tissue is that when affected it may infrequently produce metastases, even to distant parts of the body. Thus cases are on record of benign goitre, with universal metastases, and, on the other hand, of numerous metastases without any noticeable thyroidal enlargement. They occur frequently in the osseous system, and in the lungs, and when the thyroid is the site of a colloid type of goitre. The same is equally true of the malignant growths of the same tissue.

The immediate results of a total removal of the thyroid, as by operation, are myxedema, or cachexia strumipriva, conditions which require a few weeks for development and which may be preceded by an acute mania. These conditions are indicated by anemia with weakness, defective circulation, swelling of the extremities, usually first in the fingers, the swelling being of a hard, inelastic type, and not pitting on pressure, appearing later in the face so that the features become altered. Later appear also muscular tremors, with tetanoid convulsive attacks. These results of thyroidectomy may be combated by feeding thyroid extract, or by transplantation of thyroid tissue from a sheep into the tissue of the body or into the abdominal cavity. While Horsley and others have been successful with the surgical procedure, it is usually now sufficient to resort to continuous administration of thyroid extract, this being indicated only in cases where thyroid activity is defective and being contra-indicated in instances of overactivity, such as exophthalmic goitre.

THYROIDITIS.

Thyroiditis as a more or less acute affection is occasionally noted, being due to one of the infectious fevers, or occasionally following dermatitis, local infections, etc. It may assume a hemorrhagic type and be followed by production of hematoma. It may also assume a suppurative type and lead to the formation of abscess. This, if impending, is always of a serious nature, as it is sure to be followed by local cellulitis, perhaps with serious pressure symptoms, and escape of pus along the deeper fascial planes into the thorax.

An acute idiopathic hypertrophy in children has been noted by the writer in one instance, in which the enlargement was rapid, occupying but a few days, and had already caused such compression of the trachea when the case was first seen that even a tracheotomy promptly performed did not serve to save the patient’s life.

Intra-uterine hypertrophy of the thyroid is also known. There are at least five cases on record of this condition following the administration of potassium chlorate to the mother during pregnancy. In one case reported the tumor attained a size sufficient to constitute a serious complication in delivery of the child.

Among the special symptoms produced by these acute affections are: difficulty of swallowing, which may lead to great thirst; head symptoms due to obstruction to the return circulation, with congestion of the face and epistaxis; while pressure upon the pneumogastric may cause nausea or vomiting. The treatment of such a case when seen early should consist of wet and ice-cold applications for several hours; but when seen later, especially if suppuration be already threatening, pus formation and its localization may be encouraged by hot applications, followed by free incision, thus relieving tension and evacuating pus.

Thyroiditis occurring in goitrous thyroids is usually referred to as strumitis, as the enlargement itself was formerly known as struma; it follows the exanthems and fevers, and may cause sudden and distressing complications.

TUMORS OF THE THYROID.

Aside from those thyroidal enlargements to be considered under the heading of goitre may be met tumors of congenital origin, especially the simple or complicated cysts, which may grow slowly or rapidly, or may not appear at all until puberty or adult life. An apparently innocent cyst may suddenly increase in size and produce serious symptoms, or hemorrhage may occur into it, or it may rupture, in either of which instances severe pressure symptoms will ensue. All cystic tumors of the thyroid should be enucleated, an operation usually easy of performance unless the collection be multilocular and extensive. If an entire thyroidal lobe be occupied by growths of this character it may be assumed that its function has been so much impaired that it should be completely removed.

The thyroid body is occasionally the site of teratomas, i. e., tumors containing tissue of each blastodermic layer. No two such tumors are alike. They may assume various sizes and shapes, growing in various directions, and will hardly define themselves until removal.

The benign solid tumors consist mainly of the various types of goitre.

Of the malignant tumors, sarcoma is perhaps the most frequent, and is met here in all its varieties. Endothelioma occurs here also, while true carcinoma can hardly be primary in the thyroidal tissue, but may frequently extend to it and invade it, thus seriously complicating a case already made desperate by its presence in the neck. Metastatic forms of true cancer may also occur here as elsewhere. For a growth of this kind there is but one resort, i. e., extirpation, but this will be difficult and usually inexpedient.

GOITRE; STRUMA; BRONCHOCELE.

The enlargement or hypertrophy of a part or the whole of the thyroid, now known universally as goitre, has been known also as bronchocele and trachelocele. The condition is one of unilateral or symmetrical affection, met with much oftener in women than in men, and particularly in certain regions. It is most prevalent in Switzerland and in Upper India. It is occasionally known to assume an endemic or epidemic form, the affection disappearing from the region of the country concerned after a period of some years. Practically nothing is known of its cause. Many theories have been advanced, that which finds perhaps widest acceptance referring to the character of the water supply.

For present purposes goitre may be understood to include the following forms:

  • Simple hypertrophy, the so-called parenchymatous form;
  • Thyroid adenoma;
  • Cystic goitre;
  • Exophthalmic goitre (Graves’ or Basedow’s disease).

The parenchymatous form consists essentially of an overgrowth of the ordinary thyroid tissue. It is diffuse and unencapsulated, all the thyroidal tissues participating in its structure. Sometimes whole families suffer from this form of goitre, and occasionally an apparently hereditary influence may be traced. The tumor thus produced may attain great size. According as it involves one side or both will it be symmetrical or otherwise. It is elastic, smooth, rounded, sometimes apparently subdivided by furrows which mark the original lobar arrangement. It displaces the structures around it, and may attain a large size without producing serious pressure effects. When these occur they assume the type of dyspnea, dysphagia, and laryngeal paralysis. The growth is insidious, usually increases markedly with each pregnancy, and may spontaneously recede. Within it changes may occur which lead either to cystic softening and formation of cysts, or fibrous trabeculæ may appear and thus make it more firm and dense. The denser the growth the earlier the pressure symptoms appear. Occasionally the isthmus alone will appear involved, in which case there will be a central growth.

The so-called thyroid adenoma (the term adenoma being used on the supposition that thyroidal tissue is true gland tissue) is often of cystic type. It consists of more or less isolated tumors of general thyroid character, but circumscribed, often encapsulated, perhaps undergoing cystic degeneration, occurring frequently in multiple form, and producing cysts of all sizes. Such a growth will displace the other thyroidal tissue and may give a decidedly irregular aspect to the resulting tumor. The cysts often contain cholesterin. In recent cases the capsule is thin; in old tumors it may be calcified, and so may be the tissue within the capsule. These growths are seen in successive generations of the same family. They have their beginnings usually in the earlier years of life.

Similar growths may also arise from the outlying portions of the thyroid, or from accessory thyroids, so that they may be found back of the sternum, or lying deeply in the neck or near the base of the tongue. If near the surface and cystic they give a sense of fluctuation which the harder forms do not afford.

Endotracheal Goitre.

—A recent study of Enderlen has shown that small, goitrous growths make their appearance within the trachea more commonly in females than in males, and in patients of middle age. The known duration of growth has varied from a few weeks to fifteen years. He believes the majority of the cases begin to grow at the age of puberty. These growths have been found on the posterior wall of the larynx or in the trachea itself. They have usually rounded bases and broad implantation, with smooth surfaces, covered with intact mucosa. In most instances the thyroid itself is also enlarged. The only recorded symptom is dyspnea, proportionate to the degree of obstruction. They are probably to be explained by the inclusion theory, some thyroidal rest being disintegrated and so entangled as to grow in this direction. The only satisfactory treatment is ablation of the tumor, after tracheotomy, as endolaryngeal operations are more dangerous.

These constitute the ordinary types of goitre. Diagnosis is not difficult, as the resulting tumors are more or less prominent, involve the region of the thyroid, and rise and fall with each act of swallowing. When the entire organ is involved the tumor may have a horseshoe shape. Large veins appear upon the surface, while pressure symptoms will correspond with its size and location. They pursue an irregularly slow course. Many patients attain old age and a considerable size of growth without such discomfort as to require operation. Any goitrous enlargement in which considerable softening occurs, with formation of colloid material, is entitled to the term in frequent use, “colloid goitre.” By accident of location any growth of this kind behind the sternum may cause serious pressure effects before attaining large size. In symmetrical enlargement of both lobes the trachea may be so compressed as to be narrowed and to entitle it to the term scabbard trachea.

Iodine has been used externally and sometimes with benefit. The favored method in India is to use an ointment containing one grain of red iodide of mercury to the ounce. This is daily rubbed over the goitre and then the parts exposed to the bright sunlight for an hour or more. Iodine has also been used by parenchymatous injection. It is mainly used, however, by those who object to operation or do not dare perform it. The iodine treatment, whether externally or internally used, is usually disappointing. So also is that by the Röntgen rays, and, for that matter, all other non-operative measures. Operative relief alone is complete and final. It is described below.

EXOPHTHALMIC GOITRE.

As a clinically distinct type of disease this was first described by Graves, of Dublin, in 1835, and five years later by Basedow, of Magdeburg; hence it is frequently called by their names. Although the thyroid participates in the clinical picture it cannot be stated that it is primarily at fault. Three marked objective features characterize pronounced cases—thyroidal enlargement, more or less pronounced tachycardia, and exophthalmos.

So far as known there is an essentially toxemic feature behind these lesions, which is mysterious, nor is the nature of the toxemia certain. No constant lesions have been found in the nervous system, although the sympathetic nerves are always involved when the heart and the eyes are affected. The three cardinal symptoms or signs above mentioned are nearly always associated; but with pronounced rapidity of the heart’s action there may be but little involvement of the thyroid or slight protrusion of the eyes. Whatever the original toxemia, or its source, a prominent feature of the condition is hyperthyroidismi. e., hypersecretion of the substance which regulates nutrition—whose overproduction materially disturbs the heart and vasomotor nerves. It stands in strong contrast to myxedema and cachexia strumipriva, which are considered to be due to hypothyroidism or diminished secretion. Consequently it is not to be treated by feeding thyroid extract. A recent view which has much to support it is that at the basis of this condition the parathyroids are so concerned that any operation which includes their extirpation would be a serious menace. At present it may be held that the parathyroids are intermediate factors between the primary toxemia and the hyperthyroidism.

Aside from mere thyroidal enlargement, which is influenced by pressure and shows an increased pulsation, always palpable, sometimes visible, there occur increased heart activity, with a rapid and easily influenced pulse; widening of the palpebral fissures, the upper lid not following the motions of the globe, with defective convergence; rhythmic muscular tremors; increase of general sensibility; insomnia, with disturbed sleep; psychical disturbance, sometimes amounting to melancholia or mania; digestive disturbances, including diarrhea, vomiting, and thirst; cough, with frequent and shallow respiration; loss of hair and nails; sweating, flushing of surface and sometimes leukoderma or pigmentation of the skin. Terminal symptoms consist of all those mentioned above, with acute mania, high temperature, vomiting, profuse sweating, dermatitis, jaundice, and final convulsions with exhaustion, all these resembling those of death in experimental animals after the removal of the parathyroids.

A sign recently described by Teillas, which he considers pathognomonic, consists of deep-brown pigmentation of the outer surface of the eyelids, the color being evenly diffused, bounded above by the eyebrow, below by the margin of the orbit, the conjunctiva being not affected. Its effect is to apparently increase the degree of exophthalmos and to intensify the fixity of gaze observed in these subjects.

Treatment.

—This is not the place in which to consider in detail either the pathology or the drug treatment of this affection. By many surgeons it is regarded as a surgical disease, i. e., one to be treated by one of two operative methods, either thyroidectomy or excision of the cervical sympathetic. When such measures as electricity, Röntgen rays, and hydrotherapeutic treatment, and such drugs as belladonna, sodium phosphate, arsenic, iodine, phosphoric acid, etc., have failed, and when the antithyroidal serums or preparations, such as thyroidectin and antithyroidin have proved insufficient, then surgery remains a last resort. Unfortunately this is too long delayed. To remove the thyroid so soon as it is shown to be producing an injurious amount of oversecretion is neither a difficult nor a dangerous procedure, but to wait until the heart beats 150 times a minute and the patient is nearly maniacal is to wait until he is almost moribund and until it is too late. Nowhere does the remark, “The resources of surgery are seldom successful when practised on the dying,” apply more forcibly than to such cases as these.

As between sympathectomy, already described, and thyroidectomy (see below) it may be difficult to choose. By the time such a case comes to operation each will present its distinct difficulties. The question is mainly one of choice. A large tumor will obscure access to the sympathetic trunk in the neck, while, on the other hand, the neurectomy itself is probably a less dangerous procedure. The decision should be based on the predominance of the features due to vasomotor disturbances. Thus when the eyes are prominent, the pupils dilated, the palpebral fissure widely open and difficult of closure, there is reason for attacking the middle and upper cervical ganglia, which are not so difficult of access. Again when the heart is affected there would be a special indication for extirpating the inferior cervical ganglion, as well as the first dorsal; but the former will always be difficult in the presence of a thyroidal tumor, and the latter wellnigh impossible. When, however, thyroidal symptoms are pronounced, with difficulty in respiration or other purely pressure effects, thyroidectomy is indicated. This should be performed as described below. An effort should be made to preserve the capsule, at least on the inner and posterior aspect of the thyroid, in order that the parathyroids which lie in close relation to it may not be disturbed. Operations upon the vessels for the purpose of controlling the circulation are rarely practised, and the question in these cases is as between partial and complete extirpation.

Curtis has recently collected from the statistics of two German and two American operators 136 cases of exophthalmic goitre treated by thyroidectomy, with 17 deaths, chiefly from acute thyroidism. The most marked improvement realized was disappearance of tremor, nervousness, and insomnia, and of a feeling of anxiety, so common to the disease. To these may be added the more extensive experiences of Charles Mayo, which present extirpation as an almost ideal method of treatment.

As remarked above, all attempts at feeding with thyroid extract should be avoided, the case being one already suffering from hyperthyroidism. It should be noted that in few instances the thyroid seems to suffer from its own overactivity, and passes into a stage of physiological atrophy, with more or less subsidence in volume. In such a case the symptoms of Graves’ disease would gradually change into those of myxedema.

The thyroid itself is extremely vascular under all circumstances, particularly under these, to such an extent that pulsation becomes a prominent feature. This, however, should not be mistaken for that form of ordinary goitre in which the vessels undergo increase in dimensions and in which sometimes a loud bruit may be heard.

Malignant goitre implies a generalized involvement of the thyroid in one of the malignant forms of neoplasm. (See below.) It is of rapid growth, with more or less infiltration of surrounding tissues, which is evidently not of inflammatory character but more distinctive.

THYROIDECTOMY.

This may be partial or total. It is important to leave a portion of the thyroid in order that the patient may not suffer from the consequences of athyroidism, i. e., cachexia strumipriva. It is generally understood that if one-sixth or one-seventh of the total mass can be left in situ, with sufficient blood supply, it will suffice. Thus it may be possible to leave the isthmus, after removing both lateral lobes, or a portion least affected of one of the latter may be left in place.

The character of the incision will depend on the size and position of the enlargement. For complete thyroidectomy a horseshoe-shaped incision, convexity downward, should be made, extending along the anterior border of the sternomastoids and then across the neck. This should be carried through the platysma and superficial fasciæ, the anterior jugular veins being secured when cut. The flap thus made is then raised, after which a large part of the subsequent procedure is made by blunt dissection, and separation of the surrounding muscles, which are held aside with retractors. When the tumor is so shaped and placed as to make it possible it is well to approach it laterally and secure the upper and lower thyroidal vessels on one side or both, dividing between double ligatures. If this be done the mass can be drawn forward in such a way as to avoid injury to the nerves and vessels, the operator keeping in close contact with the capsule, or, for reasons specified above, perhaps dividing and shelling out the mass from within it. Although the tumor may be occupied by large vessels, those which lead up to it—i. e., the thyroids—are rarely much enlarged. Nevertheless it is wise to secure them first. While the anterior muscles may, in many instances, be separated and the tumor mass exposed between them, there are cases which will require transverse division of the sternohyoid and sternothyroid, in which case they should be subsequently sutured.

One of the complications is to find the tumor mass extending down behind the sternum or the clavicle. From these locations it should be separated by cautious blunt dissection, else the pleura or one of the deep veins might be wounded. The former accident would be instantly denoted by the passage of air and its entrance into the thorax, the latter by severe hemorrhage.

In exophthalmic cases it may be held to be especially desirable to enucleate the thyroid from within its capsule. This makes the performance easier in some respects and more difficult in others.

Extreme caution should be taken in two particular respects: First, that the trachea be not compressed, nor its caliber interfered with, by the traction efforts used in removing the mass. The second caution necessary in exophthalmic cases is to make the least possible amount of pressure upon the thyroid during the operative procedure, since, as mentioned above, its secretion is depressing to the heart, and it would complicate matters to force more of this material into the circulation at a time when everything conspires to reduce blood pressure and the reliability of the heart’s action. A certain amount of manipulation is unavoidable, but this should be made as gentle and as slight as possible. Moreover, these cases are to be drained to permit of free escape of thyroidal secretion. (Mayo.)

In performing thyroidectomy for Graves’ disease advantage should be taken of the pneumatic suit devised by Crile, and the patient placed in the semi-upright position. These are advisable precautions to take in every such operation. The position allows more natural emptying of the veins at the base of the neck and the suit permits of the blood pressure being maintained by mechanical means. In order to use the suit to best advantage the blood pressure should be noted throughout the course of the operation.

The enucleation or extirpation concluded, hemostasis should be observed, as with returning cardiac vigor secondary hemorrhage is by no means an impossible event. Every vessel which can be recognized should be carefully tied, and tissues which ooze should be caught up with suture and tied en masse. All the deeper portions of the wound should be brought together by buried sutures in such a way as to leave no dead spaces. Cases where a retrosternal pit has been left, by removal of a low-lying growth, should be drained to avoid the accumulation of blood. Where doubt exists as to security from secondary hemorrhage it is the writer’s custom to place secondary sutures, and to pack the cavity with gauze dipped in balsam of Peru, leaving this packing in place for two days, then removing it and closing the wound by utilization of the sutures.

Shock after these operations may be extreme, and is to be combated by transfusion or infusion of salt solution, with small amounts of adrenalin.

Should the surgeon attack a so-called malignant goitre he must be prepared to meet with greater difficulties and perhaps to abandon the operation before its completion. Death on the table is not unusual in such cases.

Operation under cocaine local anesthesia is often most advantageous, and is the rule in such clinics as that of Kocher, in Berne. The patient should be well narcotized with morphine, after which a weak cocaine solution is injected along the proposed line of incision. The pain produced by the balance of the work is not beyond endurance, while the dangers are certainly minimized, especially in cases where there is compression of the trachea or excessive heart action, the latter being particularly true in Graves’ disease. There is less fulness of veins, and there is neither coughing nor vomiting. The operative features are the same as those described. As the anterior thyroid artery is approached all possibility of including the recurrent laryngeal nerve in the ligature is avoided by having the patient talk, injury to the nerve producing instant hoarseness. If the growth extend low and into a pit behind the sternum it may be possible to extirpate it from above downward, and finally to lift it from its bed, securing its base or pedicle with an elastic ligature.

Fig. 500

Patient placed in semivertical position, and enclosed in Crile’s pneumatic suit, as recommended for many cases of goitre, brain tumor, or other serious operations about the head and neck. (Crile.)

A danger common to all thyroidectomies is that of injury to the trachea. This is avoided when there are no abnormal adhesions, but when the growth surrounds the trachea, or is firmly fastened to it, such an accident may happen in spite of the greatest care. According to its size and location the surgeon may endeavor to close the opening with sutures, or he may insert a tracheotomy tube or leave the wound open sufficiently to pack it snugly, preventing entrance of fluid into the trachea, at the same time expecting the wound to be subsequently closed by granulation tissue.

Sympathectomy as a measure directed toward the treatment of exophthalmic goitre, as well as of glaucoma and certain forms of epilepsy, has been described in Chapter XXXVII.

STRUMITIS.

Strumitis is a term applied to actual inflammation of an already goitrous thyroid. It may follow such infectious diseases as typhoid, or it may be an apparently spontaneous infection without known cause. It may run an acute course, tending rapidly to suppuration, in which case there will be not only pain and tenderness in the thyroid itself, but all the local evidences of pyogenic infection, with infiltration and rapid formation of pus, perhaps with widespread phlegmon of the neck. This is a serious condition and may call for early and free incision of the infected area. A hemorrhagic form of strumitis is also known. The thyroid may also be the site of metastatic abscesses in cases of pyemia, in which case there will be but few local indications.

THE THYMUS.

The thymus figures but rarely in surgical interest, but when seriously affected it causes most pronounced symptoms. Its principal activity is shown previous to birth and during the earliest months of infancy, and it should have disappeared by the age of puberty. Instead of atrophying, as it should, it may undergo hypertrophy, by which, on account of its location, serious pressure is made upon the trachea and the base of the neck. This may occur suddenly, so that a tumor in its location rapidly develops and will prove fatal unless surgical relief be afforded. This constitutes an acute hypertrophy of the thymus, which is more than a mere surgical curiosity. In one case seen by me a long trachea tube was with difficulty inserted just in time to prevent death by asphyxiation. In case of such tumor the upper end of the sternum should be removed and the tumor enucleated, or the thymus should be sewed up to the sternum and the tumor thus raised out of its bed.

The thymus is of special interest in connection with the status lymphaticus, which has been referred to in a previous chapter. Its connection in such cases with hypertrophied lymphoid elements all over the body, and especially of the adenoid tissues of the nasopharynx, was therein described, and the seriousness of the condition, with the menace which it offers to anesthesia, as well as the extreme cautions to be observed, were fully rehearsed. The significance of laryngismus stridulus and its relations thereto were also mentioned. All this is of extreme importance to the surgeon, as every child with so-called thymic asthma, and with symptoms of lymphatism, should be watched carefully and anesthetized cautiously. (See Chapter XIV.)

Acute inflammation of the thymus as well as hemorrhages within it have been observed. It may also be the site of cystic tumors, perhaps of hemorrhagic origin. Suppuration in these cases is possible. In brief, the thymus, when acutely inflamed and suppurating, may be excised, when the tumor may be removed; but when simply somewhat involved, as in the status lymphaticus, it is best let alone, except in the presence of urgent indications to the contrary.