COURSE OF MAMMARY CARCINOMA.
1. Anatomical Observations on the Extension of Carcinoma and on the Metastatic Tunzcrs.—As a rule, one glandular lobule or several adjacent lobules in a mamma are first affected. The process often remains confined to such a region for a long time, especially in the soft, tuberous form. In other cases, especially in the infiltration forms, several parts of the gland are simultaneously affected, and then gradually the whole gland. Still, the extension is in no way determined by the glandular division (of which indeed, there is often very little left), but takes place peripherally in all, or at least in several directions at the same time. As already re marked, the small-celled infiltration often precedes this, and in a certain sense prepares the way for the epithelial growth by the softening and pro per vascularisation of the tissue. In this way occurs, sooner or later, in filtration of the cutis, of the retro-mammary fascia and of the pectoralis major muscle. But this extension does not take place, by any means, to an equal degree in all directions, but frequently in the form of cords which radiate from the carcinomatous focus into the adjacent tissue, and far more frequently, interruptedly, in the form of nodules, which appear around the carcinoma as a papular exanthem, constantly spreading in wider circles around the primary focus; between these parts the tissues may remain entirely healthy for a long time, until finally, if life lasts long enough, the nodules grow into a large confluent nodular tumor. When we see this on the skin, we can, as a rule, conclude that it is the same in ternally in cellular tissue and in the muscle. By what means the growth of these nodules is limited, is, as yet, not definitely known. The suppo sitions which have been made hitherto in regard to it do not bear the test of examination. If we assume that the epithelial growth (exuber ance) is the primary step in the development of carcinoma, then we must expect that some epithelial cells are always present in the centre of the small nodules, whose exuberant growth would then be followed by a small-celled infiltration of the connective tissue. The reasons for the
presence of these epithelial cells here and there, are to be sought partly in the fact that, getting into the lymph-stream, they adhere to the valves of the lymphatic vessels, or that they undertake an independent migra tion from the carcinomatous centre, and then come to a stand-still when they cannot advance further in the lymphatic vessels on account of great numbers or too rapid growth. The most careful and lengthy examinations which I have made (a long time ago, I admit) have led to no satisfactory conclusions. If these theories be correct, however, the failures of the re searches can only be explained by the supposition that the young epithe lial cells which have swam away or migrated, are and remain so small on account of the compression exercised by the stiff cutaneous tissue, that they cannot be differentiated from the infiltrated cells. But this does not explain the presence of the nodules, which, for example, originate in the loose connective tissue between the muscular fibres. Though I have often examined such small nodules, I have never found undoubted epithe lial elements in them. It was formerly believed that the nuclei of the muscular fibres and of the nerve sheaths likewise took part in the infiltra ting growth la Weber); the exact observations of Volkmann and Sten dener have shown that this view is a delusion. The muscular and nerve fibres become atrophied by the exuberant growth of cells and the conse cutive retraction of the tissue; they pass, as I have elsewhere shown (-Arch. f. Path. Anat., Bd. VIII, Heft. 9), over into fibres which are not to be differentiated from connective-tissue fibres. After this abortive at tempt to clear up the origin of the coronary nodules around mammary carcinomas, one feels almost inclined to go back to the older view, that a peculiar irritating juice originates in the carcinoma, which penetrates the surrounding tissue, and puts it in formative excitation; but this would not contribute to the special explanation of the formation of nodules.