. Tumours, innocent and malignant; their clinical characters and appropriate treatment. other amphibians, and particularly in cuttle-fishes. Theseare known as chromatophores, and Ribbert would haveus so regard these cells in the choroid and in the skin, andhe even suggests that melanomas might be appropriatelytermed chromatophoromas. In regard to this, it is necessaryto point out that the black pigment (melanin) in the pigmentcells of vertebrates only agrees (according to MacMunn) withthat of invertebrates in the common attribute—blacknes;!The interest of Ribberts observations lies in the fact
. Tumours, innocent and malignant; their clinical characters and appropriate treatment. other amphibians, and particularly in cuttle-fishes. Theseare known as chromatophores, and Ribbert would haveus so regard these cells in the choroid and in the skin, andhe even suggests that melanomas might be appropriatelytermed chromatophoromas. In regard to this, it is necessaryto point out that the black pigment (melanin) in the pigmentcells of vertebrates only agrees (according to MacMunn) withthat of invertebrates in the common attribute—blacknes;!The interest of Ribberts observations lies in the fact that insecondary nodules of choroidal tumours found in the liverand brain, the cells were identical with the chromato- MELANOMAS 113 phores which are so characteristic of the lamina fusca elementof the choroid. The amount of melanin present in pigmented tumoursvaries greatly; in some it is so small that the tissue takeson merely a brown coloration, in others the tissues areas black as ink. The pigment particles are lodged in andamong the cells of the tumours, even in the walls of. Fig. 65.—Pigmented stellate cells from a melano-sarcoma. The cells in the lowerpart of the figure are from a secondary nodule in the liver ; the upper froma metastatic nodule in tlie brain. The primary tumour iu each instance arosein the choroid. Teased specimens {after Ribbcrt). the blood-vessels. Occasionally the secondary nodules areblacker than the primary tumour. Melanin.—This occurs as fine, irregular, amorphousgranules varying from light brown to intense black. It issoluble in ether, alkalies, and strong acids, and is bleached by\ 114 CONNECTIVE-TISSUE TUMOURS chlorine—a fact which is useful in examining the microscopicfeatures of melanomas. The urine of patients with melanotic tumours oftencontains black pigment (melanogen), usually in solution, butoccasionally suspended in the form of granules. The urine isas a rule clear when first voided, but blackens on exposureto the air, and bec
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectneoplasms, bookyear19
