Great diversity of opinion has prevailed, particularly among French authors,' concerning the changes effected in the development of fibroids by the physiological processes of pregnancy.
Many tumors are not at all affected by pregnancy. Others are materi ally changed thereby. Both conditions depend upon the seat and the structure of the tumor. The more closely connected the fibroma is with the uterus, the more will it participate in physiological processes occur ring in that organ. The closer its resemblance to the uterine tissue, the more radical will these changes be.
Sub-serous tumors are least changed by pregnancy, while sub-mucous and interstitial fibromata undergo the most marked alterations in struc ture. Again, those sub-serous fibromata which have a long, thin non vascular pedicle, are least affected by pregnancy, while the reverse obtains in the case of tumors with a broad base. The interstitial and sub-mucous fibromata which are separated from the uterine parenchyma by a stiff, firm capsule, containing few blood-vessels, undergo the least marked changes during pregnancy.
While, therefore, the degree of the changes in the tumor is chiefly de termined by the nature of its attachment to the uterus, the character of these changes will depend upon the structure of the fibroid. Pure fibro mata, composed mostly of connective tissue, are but slightly changed, if at all. They become swollen and (edematous, owing to their great vas cularity and that of the neighboring tissues. This morbid condition is frequently described as softening, and is so in reality, but must not be confounded with those metamorphoses which pathologists designate by the name softening, and which consist of actual disintegration of tissue. Vascular fibromata and those composed largely of muscular tissue, most .frequently become (sdematous during pregnancy. Those tumors which are almost entirely composed of muscular tissue, and which are not en capsulated, grow very rapidly during pregnancy by hypertrophy, and per haps by hyperplasia of their elements. The more closely identified these tumors are in structure with the uterine walls, the more do they parti cipate in the changes which pregnancy produces in the latter.
It is still doubtful whether sufficiently extensive extravasations take place in these fibromata before birth, to augment the size of the tumors, and to occasion farther changes in their tissues. In most cases these hemorrhages are probably produced by the efforts attending parturition or by the pressure of the child's head.
Cuppie ' had a unique case, illustrative of the condition under discus sion. A woman was seized in the fourth month of .utero-gestation, with violent peritonitis and symptoms of internal hemorrhage.
The diagnosis of sub-serous uterine tumor which had grown rapidly during the later months of pregnancy was made. Abortion was induced but did not save the patient. The autopsy revealed, as the cause of the fatal attack, a softened, pediculated sub-serous myoma, which had be come gangrenous owing to torsion of its pedicle.
Quite recently Dol(Tiff has asserted that the enlargement of myomata during pregnancy was due chiefly to proliferation of connective tissue; showing a tendency to undergo colloid or tnyxomatous degeneration.
The cases of growth and enlargeinent of uterine myomata during preg nancy, by one of the methods described, are numerous and authentic. The fibroids may have been so small as not to have attracted attention before the occurrence of pregnancy, and may have developed into enor mous tumors, during its progress. On the other hand, the tumors have long existed, in some cases, as small though distinct prominences, and have produced various disturbances by their rapid growth. We shall find, as a general rule, that those tumors which increase rapidly in vol ume during pregnancy, diminish with equal rapidity during the puerpe ral state.
The cases of this kind are so numerous that only the most important ones can be cited. Ingleby' mentioned these occurrences, and Mont gomery' also referred to them, but called attention to the fact that growth of the tumor does not necessarily occur.' Then followed the reports of Ashwell,' Priestley,' Hall Davis,' Madge,' Depaul, Danyau, Cazeau,' etc. Playfair,' Lorain ' and Pagan,' all had the opportunity of twice observing, in the same person, the growth and disappearance of one and the same myoma during pregnancy and the puerperal state. The cases of Spiegelberg,' of Breslau,'° and of many others should be compared with these. (Compare also Demarquay and St. Vel, Maladies de l'Ut6rus, p. 169.) Hardly a case of fibroids complicated with pregnancy is published without the statement being made that the tumor grew notably during utero-gestation. It is important, therefore, to emphasize the fact that there are numerous exceptions to this apparent rule. Gueniot," Scan zoni," Guyon, d'Outrepont, Thibaut and others, beside Montgomery, have called attention to this point.