Module 2: pigment classification and types of artefact Flashcards
artefact
introduced during processing/staining of tissue. Ie; mercury appearing when mercury containing fixatives are
used and mercury isn’t removed, or when stain isn’t filtered
endogenous hematogenous
Produced from heme
- hemoglobin
- hemosiderin
- hemozoin
- hematoidin and biliverdin
hemoglobin
stains well with eosin, seen in RBCs, haemorrhage sits, renal tubules (if a lot of hemolysis)
hemosiderin
haemoglobin breakdown product, combo of ferric iron and protein. Yellow-brown in tissues at
site of hemorhage, old myocardial infarctions, massive blood transfusions and cirrhosis
hemozoin (malarial pigment)
found in parasites and infected organs. Signet ring appearance. Demonstrated
by Giemsa stain
Hematoidin and biliverdin (bile pigments)
found at old infarct sites in heart, brain and spleen
Endogenous nonhematogenous
derived from within the body but not blood related
- melanin
- lipofuschins
- argentaffin
- chromaffin
Melanin
brown/black. Normally found in basal layer of epidermis, hair and iris. May increase in melanomas
and skin diseases
Lipofuschins
yellow/brown in H&E. “wear and tear” pigments found in aging cells of heart, liver and adrenal
glands. Stain with Oil Red O and are PAS pos
Argentaffin
found at base of intestinal glands, important in tumor and cancer diagnosis and prognosis
Chromaffin
granules found in adrenal glands as dark brown pigments used to ID tumors originating there.
Positive with Giemsa stain
Exogenous
introduced into body from outside source. Must be inhaled, ingested or absorbed
Carbon (anthracosis)
Silica (silicosis)
Asbestos (asbestosis)
Carbon (anthracosis)
black, insoluble in acid and appear in lungs
Silica (silicosis)
birefringent, appear in lung and skin of glassworkers or stone grinders
Asbestos (asbestosis)
affect lung and skin of people exposed to fibres which become coated with ferric iron (.:.
Prussian Blue pos)
