Carcinoma has, in some few instances, been found to originate from the tunica va ginalis, the glandular part of the testicle re maining for some time unaffected. Cases of the kind have been recorded by Sir E. Home-1 and Sir A. Cooper. The other two forms of cancer, colloid and melanosis, have rarely been observed in the testicle. A preparation of the former disease is contained in the Museum of Guy's Hospital. The organ is enlarged to four or five times its natural size, but pre serves its oval form : there is scarcely any trace of the natural structure remaining, its place being supplied by colloid matter. Cru veilhier has related the case of a man who died of melanosis affecting the hand, lungs, heart, stomach, and other parts. There was a deposit of the same character in each tes ticle.
Cystic Disease. — The cysts developed in the substance of the testicle and constituting this disease vary very much both in number and size, and in the appearance of their con tents. They may be only two or three in number, or they may exist in a countless multitude and occasion considerable enlarge ment of the organ. They vary in size from that of a millet seed to the dimensions of a pigeon's egg. At an early period they gene rally consist of smooth and slightly vascular cysts, closely adherent, and containing a transparent light-coloured fluid. In other cases the fluid is thick, viscid, and highly albuminous, and sometimes tinged with blood. I have never succeeded in detecting sperma tozoa in the fluid. Sometimes a small lo bulated growth arises from the walls of the cyst, and increases until it is partly or wholly filled and obliterated. The cysts usually in crease at the expense of the secreting struc ture of the testicle, which disappears or be comes much displaced. In some instances the tubular structure forms an expanded layer over the morbid mass. When inflam mation takes place, fibrine is effused be tween as well as within the cysts, and be comes organised ; so that the tumour is partly solid and partly composed of cysts containing fluid. After some time, the sur faces of the tunica vaginalis become more or less adherent, and in old cases the tumour is intersected with fibrous bands. In several specimens of the disease I have noticed small masses of enchondroma interspersed amongst the cysts. In sections the little pearly-looking masses appear as if contained within the cysts. They are however developed between them, and are closely connected with their walls. The occurrence of enchondroma in these cystic tumours has scarcely been noticed by pathologists. There are several specimens in the Museum of the College of Surgeons.
One of the specimens of cystic disease in this collection measures five inches in its largest diameter, and three inches in its smallest. Sometimes small lobulated growths arise from a part of the walls of the cyst, and in crease until the cavity is partly or wholly filled and obliterated by them, in the same manner as in cystic disease of the mamma.
The mode of origin of these cysts has not been satisfactorily made out. It has been supposed that they are formed of dilated and obstructed seminiferous tubes ; but as in cer tain cases the tubular structure exists in the form of a layer spread over the morbid mass, it is clear that the disease could not have originated in this way. This morbid change is evidently quite distinct from the little cysts so commonly developed in the head of the epididymis : indeed this part is rarely affected in cystic affections of the testicle. The dis ease is considered by some pathologists to be of a malignant character. After removal of a testicle thus diseased, tumours of a carci nomatous character have afterwards appeared in the lumbar glands and other parts. Mr. Cmsar Hawkins showed me several prepara tions of cystic sarcoma of the testicle which had been removed by operation where this happened, and it occurred also in a case which came under my own observation. The unexpected result in this instance led me to pay attention to the matter, and I am now quite satisfied that the cystic disease may be developed under two forms. In one, it occurs in combination with carcinomatous deposit : in the other and more common form, the tumour is of an innocent character, and free from the risk of disease attacking other parts after removal of the organ. In the former the cysts are larger and less numerous than in the latter. By careful examination and with the aid of the microscope the coexist ence of the two diseases may generally be made out.
Ossc deposits in the testicle. — Earthy matter occurs in the testicle under two forms : 1. Laminated, and often mixed up with car tilage ; and 2., as an inorganic deposit. In the first form it is usually deposited between the tunica vaginalis and tunica albuginea, in little bony or cartilaginous patches, in which a fibrous arrangement may be recognised. I have frequently found one or two irregularly shaped projecting ossific bodies scarcely larger than a pin's head attached to the upper part of the testicle. Ossific matter occurs also on the adherent surface of the tunica vaginalis in old cases of hydrocele, where it has been found so abundant as to form a complete ossific capsule. It has been said that the epididymis alone may be encased in bone, the testicle being free ; this I have never seen. Bony matter occurs, however, in the sub stance of the epididymis as the result of ossi fication of the product of inflammation. Earthy matter in this form is not often ob served in the substance of the testicle. The gland, however, when atrophied and reduced to a mere fibrous tissue, occasionally under goes oes both the cartilaginous and osseous trans formation. The cysts developed in the tes ticle, as I have already shown, are liable to similar changes.