Lecture 58 - Gen Path Pigments Flashcards
what are the 4 pathways of abnormal intracellular accumulations
- defect in metabolism
- defect in protein folding
- lack of enzyme (lysosomal storage disease)
- ingestion/inhalation of indigestible materials
Describe the intracellular accumulation of:
lipids
- best seen in the liver
- common in protein malnutrition, diabetes, obesity, etc.
what are the mechanisms of lipidosis/steatosis
- negative energy balance
- decreased oxidation of FFA
- decreased apoprotein synthesis
- ineffective lipoprotein synthesis
- ineffective lipoprotein transport
T/F: negative energy balance is the most common mechanism of lipidosis
TRUE
describe the gross and microscopic appearance of hepatic lipidosis
gross: enlarged liver, diffuse pallor, rounded edges, greasy
microscopic: large, discrete clear vacuoles that displace the nucleus
T/F: hepatic lipidosis occurs focally or regionally
TRUE
Atherosclerosis
cholesterol accumulation in arteries resulting from hypothyroidism or diabetes
what are the gross and microscopic appearance of atherosclerosis
gross: medium-sized arteries are firm and white
microscopic: foamy macrophages
describe the intracellular accumulation of:
glycogen
irregular borders of clear vacuoles
acquired causes = diabetes, Cushing’s, glucocorticoid admin.
what 5 pigment accumulations are seen
- red
- green
- yellow
- brown
- black
what causes red discoloration of tissue
- vasodilation, hemorrhage, hemoglobin imbibition
hemoglobin imbibition
post-mortem change
tissues uptake hemoglobin
what causes green discoloration of tissue
- old hemorrhage (biliverdin) or eosinophilic infiltrate
why is it uncommon to see green discoloration in mammalian species after hemorrhage
hemoglobin breaks down into hemosiderin rather than biliverdin
What causes brown discoloration of tissue
- hemosiderin, ceroid-lipofuscin, and melanin
when do we see hemosiderin accumulation?
- hemolytic anemias - filtering organs turn brown
- local excess - bruise, heart disease
L-sided heart disease will cause what organ to have hemosiderin build-up
Lungs
R-sided heart disease will cause what organ to have hemosiderin build-up
Liver
why are heart failure cells present in the lungs
increased pressure in pulmonary vessels from backed up blood causes erythrocytes to be consumed by alveolar macrophages
Lipofuscin
- wear and tear
- oxidative damage and age indicator
- heart and liver cells
Ceroid
- pathological pigment
- oxidative injury, nutritional panniculitis, lysosomal storage disorder
lipofuscin is commonly seen in what organ
heart
ceroid is commonly seen in what organ
intestines (“brown dog gut”)
what causes yellow discoloration in tissues
Bilirubin and carotenoid build up
write the steps of erythrocyte breakdown
- heme
- biliverdin
- bilirubin
- conjugation in liver
- urobilinogen in GIT
what causes icterus
hyperbilirubinemia
what are the causes of hyperbilirubinemia
- pre-hepatic (hemolysis)
- hepatic (liver disease; unconjugated form)
- post-hepatic (obstruction of bile flow; conjugated form)
what is the only endogenous black-brown pigment
melanin
what locations are melanin pathologic
melanocytic neoplasms
hyperpigmentation in skin
what causes black pigment in tissues
pesudomelanosis (hydrogen sulfide producing bacteria)
anthracosis (carbon dust accumulation)
amyloidosis
- protein-folding disorder resulting in insoluble amyloid
- predominantly extracellular
- local or systemic
what forms of amyloid are there
- AA (amyloid A)
- AL (amyloid light chain)
- IAPP (Islet associated polypeptide)
- AB (amyloid beta)
describe AA
- serum amyloid A (positive acute phase protein)
- hereditary to share pei, Abyssinian, and Siamese
describe AL
- derived from light chains of antibodies
- B-cell neoplasms or blood disorders
Describe IAPP
- associated with diabetes in humans
describe AB
- found in neural plaques of Alzheimer’s
describe the gross anatomy of amyloid
enlarged, waxy, pale organs
dark brown with iodine
describe the histomorphology of amyloid
pink color
present at space of disse in liver = pressure atrophy of hepatic cords
lymphoid follicles in spleen
glomeruli of kidneys = protein loss
what are the two kinds of mineralization?
- dystrophic calcification
- metastatic calcification
describe dystrophic calcification
within mitochondria or membrane-bound matrix vesicles
gross: fine, white granules or clumps
histology: basophilic, granular
describe metastatic mineralization
systemic Ca:P imbalance where the product is elevated (intercostal pleura, kidney, stomach, lungs, etc.)
what are the causes of metastatic mineralization
renal disease (↑ P)
hypervitaminosis D
bone turnover (↑ Ca)
hyperparathyroidism
PTH related protein (↑ Ca)
T/F: a functional tumor produces a hormone
TRUE
T/F: primary hyperparathyroidism is concurrent with renal disease
FALSE - secondary
