CARCINOMA. Carcinoma.—The epithelial lining of the bladder is composed of a single surface-layer of large-sized squamous cells, with underly ing pear-shaped and round-cell layers. It is also provided with small racemose mucous glands, most numerous near the neck of the blad der. It will be seen that we may thus expect to meet with two varie ties of cancer of the bladder : (a) epithelioma, or squamous-celled carcinoma, and (b) glandular-celled carcinoma. Speaking clinically, the former would usually be termed encephaloid cancer, while the latter might be encephaloid or scirrhus—in other words, soft or hard. These clinical terms, however, give no information relative to the in timate structure of the tumor, but indicate only its rapidity of growth and probable degree of malignancy. The vesical glands might be liable to innocent adenoma as well as to malignant carcinoma. So far as I know only one case of the former is recorded, viz., a case of papillary adenoma, removed by Kaltenbach" from the bladder of a woman aged forty-four years.
Dr. J. H. Neale, of Leicester, records a case" of malignant tumor of the bladder where the account of the microscopical features of the growths, to which he gives the name of adeno-encephaloid cancer, indicates a glandular as distinct from a squamous epithelial origin for the growth. The ordinary epithelioma of the bladder is a growth of variable size and extent, either limited to one spot from which it spreads, or diffuse, occurring in a variable number of patches, one usually showing evidence of being the primary growth. The tumor
is not encapsuled, but infiltrates the submucous and muscular layers, spreading to the peritoneum, the bowel, the prostate, or even extend ing to the perinum, where it forms a fungating mass. This latter is liable to occur in cases where the growth has been partially removed from the bladder after perineal section, the cancer invading the gran ulation tissue of the wound, and spreading along it to the surface.
The mucous membrane over the growth may be ulcerated and fun gous, or covered with papillary excrescences, showing no outward evidence of malignancy, or even quite smooth and apparently unal tered, in the smaller patches. The stroma of the growth, composed of the tissue of the submucous and muscular layers, with more or less round-cell infiltration, is full of alveoli well packed with epithe lial cells, following, with more or less accuracy, the types of the blad der epithelium. Psorosperms have been met with in the epithelial cells, and by some are regarded as the cause of the malignant growth. They are described and figured by Albarran in his work on tumors of the bladder ("Les Tumeurs de la Vessie," Paris, 1892). The forma tion of "cell nests" varies much in different specimens and even in different parts of the same specimen. Colloid degeneration may oc cur in primary carcinoma of the bladder, but is by no means common.