The last step in regressive metamorphosis, and one which follows closely on the heels of induration, is calcification. This process opposes a per manent barrier to the further development of these tumors, which thereby become stationary, and are, as it were, destroyed. It consists in the im pregnation of the connective tissue with lime salts, and is, in truth, an amorphous petrifaction. The salts most frequently observed are phos phates, carbonates and sulphates.
As it not infrequently happens that these calcified fibroids are expelled from the uterus, they were formerly regarded as genuine uterine calculi, and were supposed to have originated in the same way as vesical calculi. It is true that wo now and then meet with concretions in the vagina hav ing some kind of foreign body as a nucleus (a fragment of bone, more often a pessary, etc.), and thus producing some analogy with the mode of development of vestal calculi, but stones coming from the uterus are pro bably in all instances only calcified fibromata.
It is certainly astonishing that as recently as August 9, 1874, Aviettl Candura (El Siglo) could have discussed the various conditions favorable to the formation of true calculi within the uterus, asserting that the em ployment of hard water for drinking purposes was particularly noxious in this respect. But it is still more astonishing to find such an article deemed worthy of serious consideration in the columns of the Annales Gyn(cologiques, III., page 160.
Calcification usually affects the connective tissue of the tumor, and we, therefore, often find concentric strata of lime salts, generally of the phos phatic variety, usually traversing the tumor irregularly, but still following in the main the course of the bundles of fibres. It is much more rarely the case that only the outermost layers of the tumor, or the connective tissue capsule alone is affected. We can readily conceive, then, how when the connective-tissue components of a tumor become calcified, the inter spersed muscular elements are so prone to undergo degeneration, as is often observed. As both calcification and induration most frequently occur during the climacteric years, these processes are probably influenced to a great extent by the condition of the vessels of the uterine walls.
The more the nutrient vessels of the tumor atrophy, the greater the ex tent to which they are affected by atheromatous degeneration, the more readily will calcification develops. The size of the tumor seems to exercise
no essential influence in this respect, for both small pediculated, as well as large interstitial growths, have been found in a state of calcific ation. Turner (1. c.) maintains that the constitution of the pellicle and the condition of its vessels are factors of prime importance in this respect, but adduces no evidence in support of his view. That even very large fibromata may become calcified is shown by Prumet ' who spe.:ks of a tumor of this kind weighing ten kilogrammes.
In the older literature of the subject calcification has sometimes been held to be ossification, but there can be no question that the formation of bone is not met with in this connection. Nevertheless Freund' gives the following description of a tumor: " After having been sawn through, the larger tumor was seen to be of a deep yellow color, the cut surface being smooth, and developing a high degree of polish after being rubbed upon a whetstone. After being moistened with hydrochloric acid, osseous tissue with well-marked bone corpuscles was distinctly seen under the microscope in the peripheral portions of the tumor. Towards the centre there was an ordinary incrustation with lime salts, after the removal of which, by prolonged immersion in hydrochloric acid, the texture of the fatty degenerated fibroid tissue came prominently into view." With reference to the much discussed question, may fibromyomata of the uterus undergo cancerous metamorphosis, it cannot be positively de nied that such an occurrence is possible, in so far as cancerous infiltration may spread from the overlying mucous membrane to the subjacent mus cular elements. But decisive observations, at least as far as regards the development of primary carcinoma, have not as yet been reported. A combination of fibroma with carcinoma of the uterus is by no means rare, but up to the present time no instances have been reported of the isolated cancerous degeneration of a fibroid. The older reports of this nature are unreliable, in the first place because fibromata themselves were formerly classed among the malignant tumors, and secondly because sarcomata have been confounded with carcinomata.