On microscopic examination I found that the cyst spaces proceeded from enlarged gland-clusters; that very soft papillary excrescences were formed in them, which underwent muco-fatty softening after some time. Be tween these small cysts was a very distinct net-work of branched gland canals, which had an easily recognized, open connection with the cysts: this net-work was imbedded in a firm cicatrix-like connective tissue; in many places the interstitial tissue had exactly the appearance of an atro phying cicatrizing carcinoma. My explanation was as follows: new plexi form gland tubules had formed and the gland-lobules had dilated into small cysts ; I therefore chose the name " lobular cysto-adenoma." I then compared these growths with the same form of tumors in the sali vary glands. But, since the latter, after Sattler's researches, are regarded as belonging to the class of " plexiform sarcoma," I was again doubtful whether the above mammary tumor did not also belong to the " plexi form-sarcoma," and I once more examined the well-preserved preparation. I arrived at exactly the same results as before, except that my expla nation of the abnormal contents of the branched gland-ducts is now a different one. I am now convinced that these tubules are not newly formed, are not outgrowths of the already existing gland ducts during the development of the tumor, but that they are only pushed so unusually close together, partly narrowed, partly dilated, by the cicatricial contrac tion of the interstitial tissue. I formerly underestimated the signification of this cicatricial connective tissue. The radiating pains from the tumor also show the existence of a process by which the nerves are compressed or torn. Unfortunately there is nothing in the clinical history as to whether the tumor began after a certain, recognizable, immediately preceding wound ; from the anatomical examination I would deem this very prob able.
This explanation may now, perhaps, throw some light on the develop ment of the cysts. I will return to this point in the next section, and will now notice some other anatomical occurrences in the lobules of the gland: In Fig. 32 I have gathered together, without giving to it any sche matic character, several changed gland lobules, which were widely separated from each other, in order to place developmental occurrences where they me y be seen together. At b the section of an unequally widened acinus of
a lobule is seen; the partitions have become very thin, and are already partly shrunken; the epithelium, already cylindrically formed, is in part still adherent; the desquamated and mucoid softened epithelial cells have fallen out.
Before there is complete atrophy of all the fine partitions in a gland lobule, and before a faulty cyst, with few excrescences (the remains of these partitions), arises, as shown at d, there is not infrequently a con siderable growth of these papillary formations, as shown at c. The orig inal round form of the acini has become very much drawn" out. The connection of this illustration with Fig. 31 is easily apparent. The filling up of the small acini is at times so considerable, that we can really see no hollow spaces.
Since from .these descriptions it is very evident what I understand by cysto-adenoma of the mamma, and how it is anatomically developed, the classification of these few cases under " cysto-sarcoma " and " adeno cystoma " should at all events be justified. It will scarcely be advanta geous to be continually finding a name for every little departure from a once erected anatomical type, since we would also have to combine with it an exact clinical picture of the disease. Concerning this I can say nothing horn the few cases iu question. The degeneration of the gland vesicles into cysts is generally to be regarded as perhaps favorable prog nostically; it usually appears where the epithelial exuberance cannot in any way break through the boundaries of the gland vesicles; it does not come from the floating of the epithelium through the lymphatic channels, nor through infection of the lymphatic glands. Should a more solid epithelial-celled growth appear, the surrounding tissue becomes softened from cell infiltration, and if the vascular network around the gland lobules is sufficiently developed to give the epithelial growths sufficient nourishment, they easily break through their physiological boundaries and go on to the development of carcinoma with infection. It is known that this occurrence first takes place, as a rule, in the fourth decennium of life. Adenomata, which are developed at this time, may therefore be much more dangerous than those originating earlier in life.