melanosis

[Gr. melanosis =a becoming black.] Pathol.: An organic affection, in which the ti ue of the parts is converted, owing to a melanic deposit, into a black, hard, homogeneous substance, near which ulcers or cavities may form. This morbific change affects the lungs particularly. It is also met with in the liver and areolar texture. Melanosis of the lungs (or melanoma) constitutes one of the species of phthisis of Bayle; but it is impo ible to distinguish it from the other species during life. Four varieties of true melanosis have been described. ( Dunglison.) Spurious melanosis may arise from the introduction of carbonaceous matter, from the action of chemical agents, or from the stagnation of the blood.