2. PigmentsPigments
• They are coloured substances
• They may occur normally or in abnormal
circumstances
• They differ in their chemical nature, origin
and biological significance
4. PigmentsPigments
Types:
• Exogenous (coming from out side the body)
Examples:
1. Carbon (anthracosis)
2. Iron (siderosis)
3. Silica (silicosis)
4. Various pigments used in tattooing
10. Pigments - MelaninPigments - Melanin
Appears black (melas = black gr
)
Source: dendritic melanophages of the skin
Formed due to the action of tyrosinase on
tyrosine with the formation of DOPA
19. Pigments - HemosiderinPigments - Hemosiderin
• HGB derived
• Golden-yellow coloured
• Storage form of iron is ferritin/hemosiderin
• When there is excess iron ferritin forms
hemosiderin (Lysosomes)
• Demonstrated by Prussian blue reaction
(Perl’s stain)– blue black granules
23. Pigments – HematinPigments – Hematin
[Malarial pigment][Malarial pigment]
• HGB derived
• Precise composition is not known
• Golden brown granular
• Seen only in Macrophages
• Forms a complex with proteins
• Prussian blue negative
24. The chest and abdominal
cavities are opened here at
autopsy. The lungs in the
chest have a normal pink
aerated appearance with
minimal anthracotic
pigmentation, because this
80-year-old man never
smoked and never allowed
smoking in his workplace.
The mediastinum contains
mostly fat. The pericardial
sac around the heart has
not been opened.The
diaphragmatic domes
extend upward to the level
of the 6th ribs.
Virtually all cardiac diseases lead to an enlarged heart. Here is a rare example of "brown atrophy" in which the heart is small, with chocolate brown myocardium. In this condition, there is excessive lipochrome (lipofuscin) deposition within the myocardial fibers. Aging and malnutrition may favor this process, which results from cellular autophagocytosis.
8th Edition: FIGURE 1-33Â Lipofuscin granules in a cardiac myocyte shown by (A) light microscopy (deposits indicated by arrows), and (B) electron microscopy (note the perinuclear, intralysosomal location).
This is normal skin from a person with a dark complexion. The amount of skin pigmentation varies among races and individuals. Melanin is made in melanosomes in melanocytes that are interspersed with basal cells of the epidermis. The number of melanocytes is relatively constant, so the degree of pigmentation and darkness of skin in different persons is determined by the number of melanosomes and the amount of melanin pigment produced. Melanocytes interdigitate their cytoplasm with adjacent epidermal cells and transfer melanin granules to them. Ultraviolet light exposure is the signal for melanosomes to use their tyrosinase enzyme to manufacture melanin.
This is the microscopic appearance of a malignant melanoma. Large polygonal cells (or spindle cells in some cases) have very pleomorphic nuclei which contain prominent nucleoli. The neoplasm is making brown melanin pigment. A Fontana-Masson stain for melanin may help to detect small amounts of cytoplasmic melanin.
Addison’s disease.
Vitiligo-associated with other autoimmune diseases (Ex: Pernicious anemia, DM, Thyroiditis et.c.)
Pulmonary congestion with dilated capillaries and leakage of blood into alveolar spaces leads to an increase in hemosiderin-laden macrophages, as seen here. Brown granules of hemosiderin from break down of RBC's appear in the macrophage cytoplasm. These macrophages are sometimes called "heart failure cells" because of their association with pulmonary congestion with congestive heart failure.
Pulmonary congestion with dilated capillaries and leakage of blood into alveolar spaces leads to an increase in hemosiderin-laden macrophages, as seen here. Brown granules of hemosiderin from break down of RBC's appear in the macrophage cytoplasm. These macrophages are sometimes called "heart failure cells" because of their association with pulmonary congestion with congestive heart failure.
The chest and abdominal cavities are opened here at autopsy. The lungs in the chest have a normal pink aerated appearance with minimal anthracotic pigmentation, because this 80-year-old man never smoked and never allowed smoking in his workplace. The mediastinum contains mostly fat. The pericardial sac around the heart has not been opened.The diaphragmatic domes extend upward to the level of the 6th ribs.
Anthracotic pigment ordinarily is not fibrogenic, but in massive amounts (as in "black lung disease" in coal miners) a fibrogenic response can be elicited to produce the "coal worker's pneumoconiosis" seen here.
This chest radiograph demonstrates so many silicotic nodules that they have become confluent areas of silicotic nodules that have resulted in severe restrictive lung disease. This patient became severely dyspneic.
This chest radiograph demonstrates so many silicotic nodules that they have become confluent areas of silicotic nodules that have resulted in severe restrictive lung disease. This patient became severely dyspneic.
Here is a tattoo. Tattooing is a practice that is thousands of years old. In many cultures, tattoos have great significance. The pigment in tattoos is transferred to the dermis with a needle, so there can be a risk for infection. The tattoo itself over time tends to lose sharpness and intensity of color.
This tattoo on the hand still retains sharp outlines. Such a tattoo could be revised by incorporating it into a new tattoo. Removal of a tattoo can be difficult. A laser can be utilized to vaporize the pigment granules, but this is a laborious process.
This is the microscopic appearance of tattoo pigment (black) in the dermis. Note that this pigment is well within the dermis and, therefore, difficult to remove. Therefore, removing or changing a tattoo is difficult. Cosmetic surgery is not covered by insurance, either.
An infant with glycogen storage disease type Ia. Note the typical facial aspect resembling a doll's face.