hyperchromatism

[hī′pər-krōmə-tĭz′əm]
n.
  1. Excessive formation of skin pigment.hyperchromia
  2. A condition in which cells or parts of cells, especially cell nuclei, stain more intensely than normal.hyperchromasia
Related formshy′per•chro•matic (-krə-mătĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.