obstruction.' Hernial protrusion of the abdominal walls has been described by Düll: he reports two cases of this very rare occurrence; in one case, the skin covering the hernial sac became gangrenous, so that the tumour lay exposed.

B. The Interstitial remain in the substance of the uterine wall, and do not become pediculated. The appearance of such a tumour is well seen at Fig. 241. Usually there are many such tumours present (Fig. 240); Schultze counted as many as fifty in one uterus, and Thomas describes the uterus of a negress containing thirty-five.

C. The Submucous are the most important clinically. They lie imme

Submucous fibroid tumour projecting into uterine cavity (Sir J. Y. Simpson).

diately underneath the uterine mucous membrane, and project into the cavity of the uterus (Fig. 242). They are attached along a broad base, or by a pedicle; when they hang free, they are known as fibrous polypi (the most frequent form of uterine polypi, to be described in a separate chapter). When a fibroid tumour projects into the uterine cavity, it acts as a foreign body and produces uterine contractions. These lead, in some instances, to pedunculation of the tumour and even to its extrusion from the uterine cavity; in such a case, it hangs as a polypus into the vagina. In other rare cases, the capsule ruptures and the liberated tumour is expelled piecemeal-spontaneous enucleation.

Eade Lancet, December 21, 1872. 2 Cited by Schroeder, op. cit., S. 221.

CHANGES IN THE UTERUS.

The muscular wall hypertrophies, more especially when the tumour is submucous or interstitial. A small fibroid lying in the lower segment of the uterus has caused the whole organ to hypertrophy to the size of a child's head.' In submucous fibroid, the mucous membrane is also hyper

Pediculated submucous fibroid in process of extrusion (Sir J. Y. Simpson).

trophied; over the surface of the tumour, it may form adhesions or may ulcerate. The changes in the structure of the uterus generally thus resemble those of pregnancy and have been described by French writers as "Une grossesse fibreuse." Changes in the position of the uterus have been already referred to; when subperitoneal fibroids rise up into the abdo

1 Tillaux: Gaz. des Hôp., 1867, No. 144.

men, it is sometimes drawn forcibly upwards by them and may be twisted on itself. At other times the weight of a subperitoneal or interstitial tumour leads to prolapsus uteri. Inversion of the uterus is also occasioned by submucous fibroids when these are situated near the fundus and when their pedicle does not admit of extrusion as polypi.

DEGENERATIVE CHANGES.

These are the following:

Softening,

Induration,

Calcification,

Suppuration.

The softening may be due to oedema, to fatty degeneration, or to myxomatous degeneration. The occurrence of the oedema is unquestioned, and many cases of sudden increase in the size of fibroid tumours may be thus explained. From analogy with the changes affecting muscular fibre in the puerperal uterus, we should expect fatty degeneration to occur; there is, however, only a small quantity of muscular tissue present in these tumours. There are only two cases recorded in which the existence of fatty degeneration has been demonstrated by microscopic examination, although many cases are reported in which this is supposed to have occurred. Myxomatous degeneration, resulting in the formation of spaces containing mucus between the layers of the tumour, sometimes

Occurs.

2

Induration, with atrophy or shrinking of the tumour, occurs in some cases after the menopause. The muscular tissue fattily degenerates and disappears, the fibrous tissue contracts."

When calcification occurs, lime salts (chiefly phosphates) are deposited in the fibrous tissue and produce the so-called womb-stones. This deposit usually commences in the centre of the tumour and extends outwards, more rarely in the external layers so as to form a shell round the tumour. Sometimes it is so extensive that the tumour can be cut with the saw, and the cut surface polished; more usually it is incomplete, and forms a coral

1 As in the case reported by Küster: Beiträge zur Geb. u. Gyn., 1871, Bd. i., S. 7. The uterus was twisted two and a half times, so that the broad ligaments formed a spiral.

2 Gusserow Loc. cit., S. 31. The cases are reported by Freund and Martin.

3 Sir J. Y. Simpson: Obst. Mem., p. 115.

like skeleton. Calcification affects only subperitoneal and interstitial fibroids. Calcification of portions of the tumour is often accompanied with suppuration in others, probably from interference with nutrition.

Suppuration occurs frequently in submucous fibroids, as the result of injury from operative interference or from constriction of its pedicle during the process of expulsion. It has also been observed as a rare occurrence in subperitoneal fibroids, accompanying calcification or from torsion of the pedicle. In such a case, the tumour either finds its way through the abdominal walls or fatal peritonitis follows.

Whether carcinomatous degeneration specially affects fibroid tumours, is a disputed point. We occasionally find carcinomatous degeneration in a uterus where a fibroid tumour is also present (Fig. 273) or from which a polypus has on a former occasion been removed. Whether this is merely a coincidence, or whether there is a liability that the non-malignant tumour may become the seat of malignant disease, is not settled. The practical importance of this question is evident.

FIBROID TUMOURS OF THE CERVIX.

The occurrence of fibroid tumours in the cervix is rare; but, when they are present, they often give rise to difficulty in diagnosis on account

Cervical polypus springing by a fibrous pedicle from the region of the os internum, and pushing itself under the whole mucous membrane of the cervical canal; so that its insertion is partly continuous with the tissue of the uterus, partly truly submucous. Between these a cavity has formed, through tearing of the mucous membrane, so that the tumour has apparently two pedicles (Schroeder).

of the distortion which they produce. They spring from either wall, and grow outwards towards the peritoneal cavity or downwards into the cellular tissue beside the vagina. When subserous, they easily produce symp

toms of incarceration, as, from their low position, they are liable to become wedged in the pelvis. When submucous, they produce elongation of one lip and may form a polypoidal tumour in the vagina (Fig. 244); the accompanying distortion of the os externum leads to difficulty in diagnosis. Cases in which a large tumour bulges through the ostium vaginæ have been mistaken for inversion and prolapsus. Sometimes, prolapsus is due to the weight of the tumour and disappears after its removal. The interstitial form is easily mistaken for inversion when the os is converted into a transverse cleft which escapes observation and the unaffected lip is thinned out to a mere band.

ETIOLOGY.

Gusserow, to whose exhaustive article-Die Neubildungen des Uterusin Billroth's Handbuch we are greatly indebted in this chapter, says in regard to etiology, "Ueber die Ursachen der Uterus-myome wissen wir so wenig, wie über die Ursachen der meisten pathologischen Neubildungen, nämlich nichts" (of the causes of fibroid tumours we know as little as of the causes of most pathological new formations, that is nothing). Virchow and Winckel have both made elaborate attempts to assign a cause to the development of fibroid tumours. The number and variety of causes adduced by these observers only show how far we are from the knowledge of the real cause; with such a variety of causes, the difficulty would not be to explain why they are present in some but why they are not present in every case.

They are without doubt the most frequent new formation in the uterus. Klob says that they are present in 50 per cent. of women who die over fifty years of age; and Bayle, in 20 per cent. of those who die over thirtyfive years; both of these estimates are probably beyond the mark.

Their development is in some way related to the development of the sexual apparatus. Thus, there are no well-authenticated cases of their arising before puberty or after the menopause. The majority of patients are between the ages of thirty and forty when they first seek medical advice, as is evident from the accompanying table based on statistics collected by Gusserow (Fig. 245). Schroeder says that of 196 patients, who during three years of his private practice consulted him for fibroid tumours, 104 were between forty and fifty, and 62 between thirty and forty.

'Barnes: Obst. Trans., iii., p. 211.