This section is from the book "A Manual Of Pathology", by Guthrie McConnell. Also available from Amazon: A Manual Of Pathology.
Pigmentary Infiltration is the deposit of pigment within the tissues.
According to their origin, pigments may be divided into four classes:
1. Those derived from outside of the body.
2. Those formed from hemoglobin and its derivatives, the hematogenous pigments.
3. The hepatogenous or biliary pigments.
4. Metabolic pigment; that resultiug from cellular activity within the body is known as melanin.
The hematogenous pigments are three - hemoglobin, hemosiderin, and hematoidin.
Pigmentary Infiltration is often met in old people. The muscularis is filled with a yellow pigment that does not contain iron. The intestine may become very dark as a result of the use of bismuth paste in surgery.
Hemorrhoids are varicose veins of the rectum. They may be either internal or external in character, according to their relation to the sphincter ani. Are commonly the result of interference with the venous circulation. They may be due to cirrhosis of liver, pressure from tumors, or from chronic constipation. The feces not only press upon the veins, but also give rise to a chronic proctitis that weakens the vessel walls. The hemorrhoids appear as small, dark bluish projections which on section are found to be formed of dilated veins, between which is usually a formation of fibrous tissue. The cavity may occasionally become filled with fibrin and be converted into a fibrous mass. Hemorrhage frequently accompanies hemorrhoids, and infection with inflammation is also common.