1. Arrest And Excess Of Formation

Froriep has lately recorded an extremely rare case of absence of one of the mammary glands in a female; the muscles and bones of the corresponding or right side of the thorax were imperfectly developed. The mammae are found imperfectly developed in those cases in which the sexual apparatus generally is defective, and where certain parts of the latter, or the entire individual, present an hermaphroditic appearance, approaching the male type. An excess of development occurs in various degrees and forms: in the first instance we find an increase in the number of nipples, one gland being provided with two or three; or there may be supernumerary glands, a third one being placed under one of the normal or between the two breasts. Sometimes the accessory gland is situated externally in the armpit, or there may even be a third, fourth, and fifth, which are arranged symmetrically under the normal breasts, and are always smaller than the latter. We include under this head also, the precocious development of the mammae in premature puberty, as well as the development occasionally found in the mammae of man approaching the female character, either with or without an arrest of development in the genital organs. An excess of development is occasionally simulated by the gland being separated into several lobes.

2. Anomalies Of Size

In addition to the anomalies spoken of at the end of the preceding section, we here allude to the increase in the size of one or, more commonly, of both breasts, developed spontaneously or after sexual excitement in either sex, or in the female sex after parturition. It consists in a hypertrophy of the gland and of the surrounding fat. The enlargement may attain a most extravagant extent, so as even to overwhelm the powers of growth in other parts. Hypertrophy of the gland is very often introduced by violent congestion, and accompanied by a secretion of milk.

A diminution or atrophy of the gland, as a morbid process, occurs in the shape of premature involution, both in consequence of the effects of over-nursing, as well as from the sexual functions being completely in abeyance.

3. Diseases Of Tissue

1. Inflammation

Inflammation of the mammary gland occurs very rarely, except in consequence of various causes that operate during the puerperal state, and during suckling.

The gland is never attacked throughout, but the inflammation appears at distinct spots of various dimensions, or is, as it were, reduced to them in the course of its progress; and whilst it is here developed with greater intensity, becomes moderated and recedes at all other points. Its symptoms are, besides tumefaction of the gland at the seat of disease, congestion and reddening, by which the natural appearance of the gland is obliterated, and made to resemble flesh: there is also hardness and resistance, with increased density of the parenchyma, which has lost its toughness, and has become friable and lacerable. The gland is infiltrated with a coagulable product, containing more or less reddish serum. Cure may ensue by resolution or absorption of the product, or the process may pass into more or less considerable induration, which at times is very obstinate, or, again, it may terminate in suppuration or abscess of the gland.

Inflammation of the mammary gland not unfrequently coexists with one of the above-described puerperal diseases, though there is no essential relation between the two affections. The resulting abscess is to be carefully distinguished from the deposition of pus, consequent upon its absorption in metrophlebitis.

2. Cirrhosis Of The Mammary Gland

There is a certain condition of the breast which, from all that we know of it, seems comparable to cirrhosis of the liver and the lungs (bronchial dilatation). We have been unable to ascertain whether any particular disease gives rise to it, but there is every reason to suppose that it is the result of protracted suckling.

3. Adventitious Growths

A great variety of adventitious growths occur in the mammary gland; some of these are unusual, whilst others are very frequent. They affect mainly the female breast, and only exceptionally, and from very remarkable influences, the male breast.

A. Cysts

The simple cyst, with serous, albuminous, or colloid contents, as well as the adipose cyst, with or without the formation of hair, is very uncommon; the compound cyst is equally rare. Not so, however:

B. Sarcoma

This is of common occurrence, and it often assumes the shape of encysted sarcoma, the cysts being either simple, or presenting the endogenous development of secondary cysts; this form is the hydatid tumor or hydatid mammary carcinoma of English writers. All the sarcomatous growths are liable to attain a considerable size, they are frequently recognized as such, and may be extirpated successfully.

C. Fibroid Tumors And Enchondroma

These are not frequent; we have observed the former a few times, but only of small dimensions. Johann Miiller has seen one instance of the latter.

D. Tubercle

According to our own observations, tubercle never occurs in the mammary gland.

E. Cancer

Cancer, on the other hand, which is found to occur in almost all its varieties, is the more frequent; mammary and uterine cancer alone suffice to give to the female sex a vast preponderance over the male sex, as to the frequency of cancerous affections. The different forms may occur by themselves, or in combination with one another; medullary carcinoma is particularly liable to form upon a scirrhous matrix.

a. True scirrhus, or fibrous cancer, and the following variety, are the most common. Scirrhus presents the well-known characters of a carti-tilaginoid, immovable, nodulated, branched tumor, which draws in the integument, and more particularly the nipple, with its areola, and is imbedded in fat. Its internal structure presents a lobulated appearance, and consists of a whitish fibrous stroma, and of a gray transparent crystalline substance, which is deposited in the interstices of the former. It is often traversed by lacteal ducts which contain a corrugated, whitish, or yellow cheesy matter. The ulcer that it gives rise to is cup-shaped, and presents a hard elevated margin and a sanious discharge; extends in all directions, but especially backwards, so as to involve the pectoral and intercostal muscles, the periosteum of their ribs and their bony structure, and at last to fix itself immovably in the thoracic parietes. The margin as well as the base of the ulcer degenerate into a red, vascular, bleeding fungus, which is distended by a whitish encephaloid juice; the immediate consequence is a development of lardaceo-medullary tumors in the most various tissues, either in the vicinity or at a distance. This constitutes:

/3. Medullary carcinoma, which however occurs not only in combination with fibrous carcinoma, but also in a primary form; in the latter case it is equally distinguished by its rapid growth, its large dimensions, by the much more speedy degeneration into universal cancerous cachexia, and by the sponginess of the ulcer.

y. Cancer hyalinus is much less frequent than either of the former varieties; it occasionally attains a considerable size, and has, in addition to other peculiarities, a remarkably lobulated structure.

Cancer of the mammary gland is generally developed after the thirty-fifth, though it is sometimes met with before the thirtieth year. It frequently exists by itself, but is more commonly combined with cancer of the adjoining axillary glands, with mediastinal, pleuritic, pulmonic, uterine, hepatic, and cerebral cancer, with universal cancerous cachexia, and with mollities ossium.