The enlargement of the breast, which normally prepares it for lactation, is to be regarded as the development of a normal or physiological adenoma. Anything which simulates this under other conditions is abnormal, and any overdevelopment of true mammary gland tissue, when localized and circumscribed, should be referred to as adenoma. In such tumors cystic changes often occur, as well a later transformation into adenocarcinoma, something always to be dreaded. These changes are more likely to take place during lactation, at which time the blood supply to the breast is more free. The development, then, of an adenoma in the breast of a nursing woman should be regarded with suspicion, and unless benign it should be regarded as demanding removal of the entire organ. These tumors also are non-adherent and lack the ordinary signs of malignancy.
Cancer of the Breast.
—Cancer occurs in the breast more often than anywhere else, and carcinoma constitutes about 85 per cent. of these malignant tumors, the balance being mostly sarcomas, the remaining small number being made up of endotheliomas and the other rare forms. The most common type of carcinoma is the so-called scirrhus, in which there is a large amount of dense stroma, and which forms a strong contrast with the rare forms of rapidly growing, true soft cancer—i. e., the encephaloid or medullary as they used to be called—in which the cancer cells proliferate with greater rapidity and in which there is a small amount of stroma, so that in consequence the tumor itself is soft or almost gelatinous.
Sarcoma of the breast may assume either of its well-known types, and is a tumor seen in the earlier rather than in the later years of life. It sometimes grows rapidly and attains large size, seeming to approach the surface more rapidly and readily than ordinary forms of carcinoma. In consequence it may be mistaken for abscess. As a rule, however, the skin is not so likely to be adherent to the tumor as in carcinoma, and the lymph nodes are not so early involved, while in a cut section of the tumor the fat is not so disposed as in carcinoma, where it may be seen in layers, while in the former case it has been transformed into malignant tissue.
The two principal forms of carcinoma are the acinous and the tubular, in the former the cells being packed into the alveoli and surrounded with a firm and adventitious stroma, while in the latter the primary development seems to be within the milk ducts, which being first involved cause a more multiple minute invasion and a less distended tumor formation.
The general indications of cancer in the breast are as follows:
The presence of tumor, sometimes of regular and definite outline, sometimes diffuse and not easily outlined.
Fixation of this tumor in the surrounding tissues in such a way that it cannot be moved without disturbing them.
Fixation of the general area, either to the skin above or to the pectoral fascia below, or both. This gives to the part an immobility in contrast with normal conditions.
Retraction of the nipple, when the growth is large or located near it. This is a feature perhaps not noticeable in the primary stages when it is so important to recognize the disease if present.