�ݺ�ߣ

Prof.Dr.
Khalil Hassan Zenad
Aljeboori
Copyrights©2017lAliraqiaUniversitylDentistrylPathologylProf.Dr.KhalilHassanZenadAljeboori.
DISTURBANCES OF
PIGMENTATION
Lecture 4

Pigment are colored substance either
exogenous or endogenous.
Disturbances of Pigmentation

1. Carbon in coal dust, air pollutant when inhaled by
phagocytes (macrophages) (alveolar macrophages) to
regional lymph node and in pulmonary parenchyma
(anthracosis) in excessive amount cause coal workers
pneumoconiosis.
2. Tattoing :form of pigment (tattoos pigment) in skin by
needle or by sharp instrument .
Exogenous pigments :

1- Lipofuscin or wear- Tear pigment: brown yellow granules intracellularly accumulated in
heart, liver and brain, this pigment composed of lipid and protein derived peroxidation of
unsaturated lipid of body during starvation , malnutrition = brown atrophy.
2- Melanin : Endogenous pigment brown – black induced by catalyzed oxidation of tyrosine to
dihyroxyphenylalnine, it form in melanocytes located in epidermis protect the body against
ultraviolet radiation, absence of melamine termed albinism, in melanoma , nevus and freckles
the melanine deposited due to focal melanoblasts proliferation .
3- Hemosiderin : Is brown pigment of red cells in which hemoglobin break down in too much
amount the pigment contain iron either free or phagocytosed macrophages, also appear in case
hemorrhagic anemia , blood transfusion and passive congestion, the pigment occur in different
organs , in case of increase absorption of high iron diet . ( when excessive hemosiderin which
more extensive accumulation of iron are seen in hereditary hematochromatosis in skin and
viscera in which tissue injury, fibrosis, heart failure and diabetes mellitus occur) .
Endogenous pigment:

Ochronosis : Melanine pigment affected the cartilage, of ear,nose , may be
congenitally .
Bilirubin: Is the pigment of bile derived from Hb but unlike hemosiderin
contains No iron . In hepatocytes changed into bilirubin, jaundice occur
when too much bilirubin resulted from extensive lysis of RBCs or damage
of hepatocytes or obstruction of bile ducts .
Hematoidin: Is close to bilirubin formed in tissue from Hb like hemosiderine
its formation is intracellular but need several days to occur in lacking O2
tissue, in dead tissue usually occur.
Hematin: When break down of blood red cells is formed by direct action of
acids or alkalies on Hb, is not precursor for hemosiderine or bilirubin .
Malarial of pigment : Like hematin effect parasite on RBcs, Hb.

Calcification :Characterized by abnormal deposition of calcium
salts mainly in the dead tissue it is present in 2 type :
1. Dystrophic calcification : occur in dead tissues , grossly chalky like materials and gritty
sound during cutting.
Microscopically: intra and extra cellular basophilic deposits , plates like.
2. Metastatic calcification :Seen in cases of hypercalcemia due to :
A. Increase level of parathyroid hormone .
B. Destruction of bone example in pagets disease in which bone turnover occurred.
C. Vitamin D disorders or intoxication.
D.Renal failure.
*Metastatic calcification occur through all body organs .
Disturbances of minerals

Is the deposition of crystals of uric acid and urates in
cartilaginous, ligament about joints, synovial
membrane and viscera . such as heart valves, kidney,
the uric acid and urates may deposited in kidney
collecting tubules or in renal cortex form granuloma.
Uric acid derived from nucleoproteins of food , when
the disturbance of purine metabolism uric and urates
were deposited .
Gout

�ݺ�ߣ

Lecture 4 disturbances of pigmentation

More Related Content

Lecture 4 disturbances of pigmentation