Ch. 5 morphology boxes Flashcards
Most striking feature of marfan syndrome?
skeletal abnormalities
Describe skeletal abnormalities of those with marfan syndrome?
- unusually tall
- exceptionally long extremeties
- long tapering fingers and toes
- joint ligaments in hands and feet are lax (double jointed)
- Dolichocephalic (long-headed)
- spinal deformities
- pectus excavatum or a pigeon breast chest
What is the most characteristic ocular change of marfan syndrome?
bilateral subluxation or dislocation (usually outward and upward) of the lens, referred to as ectopia lentis
What is the most life threatening feature of Marfan syndrome?
cardiovascular lesions
What are the two most common cardiovascular lesions of Marfan Syndrome?
1: mitral valve prolapse
2: dilation of the ascending aorta due to cystic medionecrosis
In Marfan Syndrome, weakening of the media predisposes to an intimal tear, which may initiate an intramural hematoma that cleaves the layers of the media to produce what?
Aortic dissection
What dominates the clinical picture of GM2 gangliosidosis?
involvement of neurons in the central and autonomic nervous systems and retina.
Describe the histological presentation of neurons in GM2 gangliosidosis.
Ballooned with cytoplasmic vacuoles, each representing a markedly distended lysosome filled with gangliosides
What stains are positive in GM2 gangliosidosis?
Stains for fat such as oil red O and Sudan black B
What can be seen by electron microscope in GM2 gangliosidosis?
cytoplasmic inclusions, most prominent being whorled configurations within lysosomes composed of onion-skin layers of membranes.
What happens to the ganglion cells in the retina, particularly at the margin of the macula in GM2 gangliosidosis?
They become swollen
What is a characteristic finding of Tay-Sachs disease and other storage disorders affecting the neurons?
A cherry-red spot appears in the macula
What type of mutation is involved in Niemann-Pick type A?
missense mutation that causes almost complete deficiency of sphingomyelinase
Describe the cell in Neimann-Pick Disease type A.
- Affected cells become enlarged due to the distention of lysosomes with sphingomyelin and cholesterol.
- Foamy cytoplasm
In frozen sections of fresh tissue in Niemann-Pick Disease type A what do the vacuoles stain for?
Fat
Describe what you see on electon microscope of Niemann-Pick Disease Type A
-Confirmation that vacuoles are engorged secondary lysosome that often contain membranous cytoplasmic bodies resembling concentric lamellated myelin figures sometimes called ZEBRA BODIES
What organ is often massively enlarged in Niemann-Pick Disease?
Spleen
What happens to Gyri and sulci of the brain in Niemann-Pick Disease type A?
gyri shrink and sulci widen
Describe the neurons in Niemann-Pick Disease
Vacuolation and ballooning of neurons
How prevalent is a retinal cherry-red spot in Niemann-Pick Disease?
1/3 to 1/2 of individuals
In Gaucher disease, where are the distended phagocytic cells known as Gaucher cells found?
Spleen, Liver, bone marrow, lymph nodes, tonsils, thymus, and peyer patches
Describe the Gaucher cells
- fibrillary type of cytoplasm likened to crumpled tissue paper
- enlarged
- one or more dark eccentrically placed nuclei
what type of staining is positive in Gaucher cells?
Periodic acid-Schiff staining
What is seen with an electron microscope of Gaucher cells?
The fibrillary cytoplasm can be resolved as elongated, distended lysosomes, containing the stored lipid in stacks of bilayers.
Describe the spleen in Gaucher Disease?
enlarged, sometimes up to 10 kg
Describe the lymphadenopathy in Gaucher Disease?
Mild to moderate and body-wide
Describe the bone pathology in Gaucher Disease?
- Produces areas of bone erosion that can give rise to pathologic fractures
- Bone destruction occurs due to the secretion of cytokines by activated macrophages
Where are Gaucher cells found in patients with cerebral involvement?
- Virchow-Robin spaces
- arterioles are surrounded by swollen adventitial cells
in MPSs, where are the accumulated mucopolsaccharides generally found?
- mononuclear phagocytic cells
- endothelial cells
- intimal smooth muscle cells
- fibroblasts
What are the common sites of involvement in MPSs?
- spleen
- Liver
- bone marrow
- lymph nodes
- blood vessels
- heart
What do cells look like microscopically in MPSs?
distended and have apparent clearing of the cytoplasm to create so called “balloon cells”.
Describe what is seen under the electron microscope in MPSs.
The clear cytoplasm can be resolved as numerous minute vacuoles. These are swollen lysosomes containing a finely granular periodic acid schiff positive material that can be identified as mucopolysaccharide.
Some of the lysosomes in neurons of MPSs are replaced by what?
Lamellated zebra bodies similar to those seen in Niemann-Pick Disease.
What are the common features that run through all MPSs?
- hepatosplenomegaly
- skeletal deformities
- valvular lesions
- subendothelial arterial deposits, particularly in the coronary arteries
- lesion in the brains
What are the important causes of death in MPSs?
myocardial infarction and cardiac decompensation
