Medullary Carcinoma ordinarily assumes the form of roundish tumors; not rarely, however, both primarily and consecutively, that of infiltration into the parenchyma of every variety of organ. To the naked eye, the tumors often seem sharply sundered from the surrounding textures. Nevertheless, the impossibility of dissecting them out, without injury to those textures, and a narrower scrutiny, teach us that they penetrate into neighboring textures, and moreover, that they grow in suchwise as to infiltrate and destroy the textures in their immediate circumference. In other cases, however, they are capable of being shelled out of an organ, Laving a very delicate, areolar tissue-like, vascular sheath. Such growths are generally furnished with a membranous stroma, are more or less distinctly lobulated, grow independently, and simply jostle the textures out of their place.

Medullary cancer in the one case grows to an enormous volume, in the other case is remarkable for its numerical dissemination. Its increase in volume, especially when rapid, takes place through the accession of embryonic elements. Hence the circumstance that old medullary carci-nomata which suddenly undergo great augmentation of volume, have, at their base only, a solid and textural stroma, or it may be a bony skeleton. Medullary carcinoma is, both in its development and in its subsequent course, the most acute of all cancers. As a solitary growth in the organism, it arrives very rapidly at its full volume, and throws out a multitude of secondary tumors with the same celerity, not unfrequently under the accompaniment of very acute typhoid fever. The more hurried its development, the more does the embryonic form (elementary granule, nucleus, fluid intercellular substance) of its elementary composition, that of genuine encephaloid, predominate. Wherever cancer-production is acute, its form is the medullary.

Conformably with this, every other cancer, goaded into redundant growth, degenerates into the medullary, that is, enters into combination with the latter, the new accession being the medullary. The fungus upspringing from the ulcerating base of a cancer, is in its nature medullary. Every consecutive, every general, cancer-production is invariably medullary, nor is there any organ in which medullary carcinoma does not occur, either primitively or consecutively, as part and parcel of general cancer production.

In point of fact, medullary carcinoma occurs in organs in which no other cancer, least of all fibrous cancer, ever occurs; as in the liver, the kidneys, the lungs, the testicles, the lymphatic glands.

In the bones, medullary cancer is frequently distinguished by a lamina-stellate, thorny bone-skeleton, the form often obviously depending upon the nature and arrangement of the stroma. Sometimes it causes the bone to rise up into a bone-capsule; more frequently, however, it dissipates it into a voluminous honeycomb mass.

In medullary carcinoma the cancer-crasis has attained its highest grade. It experiences a further augmentation through infection, - through reception of this, the most readily absorbed cancer blastema, into the lymphatics and bloodvessels. The products of inflammation placed under its influence are eminently albuminous, white, opaque exudates, and these become developed into medullary cancer, upon serous membranes, or as cancerous lung hepatization, and the like. The same thing happens with respect to coagula within the vascular system, both in the greater vessels and in the capillary system; by dint of an alienation of the fibrin, they bear evident marks of the cancerous character - cancerous phlebitis, capillary phlebitis (deposit).

We cannot subscribe to the assumption of regular stages of medullary cancer, of a stage of crudity, of softening, of ulceration, etc, these being conditions not correlated by any necessary causal links.

That which is regarded as crude medullary cancer, is the variety furnished with a consolidated intercellular substance. Softening obviously characterizes the form of medullary cancer luxuriating as the true encephaloid, and it attaches equally to that which originates at once as such. Lastly, the ichorous and ulcerous destruction of the structure is a consequence of its inflammation, that is, of accidental disease of the tumor.

Medullary carcinoma frequently destroys life as a consequence of its surpassing growth, either as a solitary alien formation, or as one distributed over several organs, - through cachexia and exhaustion, through hindrance to the function of important organs; for example, of the digestion, of the larger veins, - the vena cava, by its closure; again through hemorrhage; finally, through inflammation and ulceration, often under the symptoms of cancerous infection of the blood.

The substance constituting the reticulum occurs, especially in the softer forms of medullary carcinoma, in large accumulated masses. In the forms furnished with a fibrous or membranous stroma it follows for the most part the distribution of the latter, and therefore of its bloodvessels.

Contradictory as it may seem, after what has been stated, in no cancer is a spontaneous or natural process of cure brought about so frequently as in the medullary.

Such a process is the sudden and rapid destruction of the cancer by ulceration and necrosis, as observed not unfrequently in the dead subject, in medullary cancer of the womb. Such a process, again, is the metamorphosis described, under the general heading of "Cancer," as saponification and incrustation. Moreover, it is known as a fact, that medullary carcinoma in the subcutaneous fat-layer will disappear through resorption, and return again.

With reference to the fungus haematodes of Wardrop, and the medullary carcinoma of Abernethy, we feel compelled to subscribe to Walter's verdict, namely, that they are identical. For we have always found the former to resolve itself, when closely examined, into medullary carcinoma with luxuriating vascularity. Assuming, therefore, the term "fungus nematodes" to designate a mere accidental condition of medullary carcinoma, there might be no impropriety in abandoning it, or in understanding by it only a highly vascularized medullary carcinoma.

On the other hand, it is requisite to bear in mind that which we have stated under the head of bloodvessel formation, namely, that assuredly there are alien growths, which, although primitively mere bloodvessel luxuriations, may subsequently combine with cancer, and this possibly without any concurrent anomaly of the general crasis, through mere impairment of the blood held within their own capillary system. We must here once more refer to the results of Van der Kolk's injections of the growths in question, which induced him to discriminate between fungus haematodes and medullary carcinoma.

That medullary carcinoma has some sort of affinity to the medulla of the nervous system, appears, not alone from its general aspect and chemical composition, but also from the fact that, in medullary cancer of the eyeball, the tumor springs from either the retina or the optic nerve, and that nerves speedily perish within the range of medullary tumors.

To medullary carcinoma we shall annex, as varieties, certain growths which bear an affinity to it.