STANLEY ROBBINS MD in his office Boston University

STANLEY ROBBINS, MD, in his office, Boston University School of Medicine in 1978

Intracellular accumulations of endogenous or exogenous substances - Lipids: fat may accumulate in the liver as fatty change - Proteins: abnormal protein accumulation is often irreversible. - Glycogen: glycogen storage diseases - Complex Lipids: sphinglolipidoses and other lipid accumulations

Intracellular accumulations of endogenous or exogenous substances - Complex carbohydrates: mucopolysaccharidoses and other complex carbohydrate diseases. - Minerals: iron, as hemosiderin, or carbon, as anthracotic pigment - Pigments: lipofuscin is a benign brown pigment of lipid origin that may accumulate with age, or melanin from melanomas, or bilirubin as in jaundice

Fatty Change • Hepatic lipid accumulation is characterized by intracellular accumulation of triglycerides, and due to the failure of metabolic removal. • Defects in fat metabolism are often induced by alcohol consumption, and also associated with diabetes, obesity, and toxins. • Fatty change is most often seen in the liver (and heart), and is generally reversible.

FATTY CHANGE – Gross features • hepatomegaly • pale, yellow color • greasy appearance

FATTY CHANGE – Microscopic features • Fat vacuoles coalesce and displace the nucleus to the periphery of the cell • vacuoles appear clear, with well-defined edges • lipid accumulations must be distinguished from accumulations of water or glycogen, using special preparation and stain – Oil Red. O.

Calcification • Dystrophic calcification – Abnormal calcium deposition in dead or degenerating tissues • In areas of necrosis • Atheromas of advanced atherosclerosis

Calcification Metastatic calcification – Abnormal calcium deposition in “normal” tissues secondary to hypercalcemia (in soft tissues that are not the site of previous damage )

Metastatic Calcification – Hyperparathyroidism – Destruction of bone tissue – Vitamin D related disorders – Renal failure

Morphology With H&E stain : basophilic amorphous granular appearance Von Kossa stain – black deposits

Amyloid Congo red-stained amyloid shows light green birefringence when subjected to polarized light.

Lipofuscin • “Wear & tear” pigment • derived through lipid peroxidation of polyunsaturated lipids of subcellular membranes • accumulates in tissues undergoing slow, regressive changes – common in liver and heart of aging patients or patients with severe malnutrition and cancer cachexia • appears as a yellow-brown, finely granular, intracytoplasmic (or perinuclear) pigment

Lipofuscin/ceroid (Latin: fuscus=brown, “brown lipid”) Brown discoloration of intestinal muscle due to vitamin E deficiency and smooth muscle lipofuscinosis

Haemosiderin • • derived from hemoglobin golden yellow, granular or crystalline pigment storage form of iron forms in response to local or systemic excess of iron ferritin forms hemosiderin granules • local excess: from gross or minute hemorrhage (eg. Bruise) • systemic excess: from increased absorption of dietary iron, impaired use of iron, hemolytic anemia, transfusions

Hemosiderin Chronic passive congestion with hemosiderosis and edema in a lung

Hemosiderin Chronic passive congestion with hemosiderin in alveolar macrophages

PRUSSIAN BLUE

Bilirubin

Bilirubin (bile) casts in hepatic canaliculi in chronic liver disease

Melanin (Greek, melas=black)

Melanin (Greek, melas=black) Melanin in melanoma tumor cells