Pathology Flashcards
What is the most important disease affecting the joints?
osteoarthritis
aka degenerative joint disease (DJD) and Rheumatoid Arthritis (RA)
What are important metabolic causes of arthritis?
1) gout
2) pseudogout
What are the classifications of osteoarthritis?
1) primary: unknown cause; “wear and tear arthritis”
2) secondary: develops under certain other conditions
What accelerates osteoarthritis?
1) mechanical instability
2) stress on joint
3) increased stress of joint surface
What is fibrillation?
formation of vertical clefts from cartilage in early stages of osteoarthritis
What happens to the articular cartilage in osteoarthritis?
1) softening
2) surface defects
3) irregular thinning
What is eburnation?
continued pressure induces sclerosis of subcohondral plate in osteoarthritis
What are bone cysts?
cysts filled with synovial fluid formed by bone degeneration under stress in osteoarthritis
What are osteophytes and where do they form?
spurs of new bone which for at the margins of the joint of subchondral bone in osteoarthritis; causes narrowing of joint space
What are pathologic features of osteoarthritis?
1) spine involvement (cervical/lumbar stiffness; bone spurs and osteophytes “lipping”)
2) hand involvement (nodular deformities: Heberden’s and Bouchard’s)
3) feet involvement (toe deformities: bunions at 1st MTP joint)
Is serologic data usually positive or negative in Rheumatoid arthritis?
positive
What does the initial inflammation begin as in Rheumatoid arthritis?
synovitis; leads to exudation of fluid and inflammatory cells into joint cavity
What is contained in the inflammatory infiltrates and the joint fluid in Rheuatoid arthritis?
inflammatory infiltrates: lymphocytes and plasma cells
joint fluid: lymphocytes, plasma cells, and neutrophils
What does the inflamed synovium lead to pathologicaly in Rheumatoid arthritis?
Pannus; exuberant synovial fronds transformed into granulation tissue
What do the inflammatory cells of the pannus release in Rheumatoid arthritis?
1) lytic enzymes
2) inflamatory mediators
What role do inflammatory mediators play in Rheumatoid arthritis?
1) destroy cartilage
2) erode underlying bone
What is ankylosis?
inflammatory mediators in RA cause joints to be immobilized and intraarticular space becomes completely obliterated as granulation tissue transforms into collagenous scar
What is the clinical presentation of RA?
1) joint pain
2) swelling
3) redness
What are characteristic findings of the wrist in Rheumatoid arthritis?
1) ulnar deviation of wrist
2) deviation of fingers in opp. direction
3) anterior slippage of proximal phalanges (“Z-Deformity”)
What are other names for “Z-Deformity”?
1) swan neck deformity
2) boutonniere deformity
3) hourglass deformity
What are constitutional signs and symptoms of Rheumatoid arthritis?
1) low-grade fever
2) loss of appetite
3) malaise
4) fatigue
5) anemia common
What are Rheumatoid Nodules?
subcutaneous nodules; seen in many anatomic sites besides joints; composed of central fibrinoid necrosis surrounded by macrophages nad lymphocytes
What is Pigmented Villonodular Synovitis?
benign tumor of synovial lining
What is the characteristic of pigmented villonodular synovitis?
exuberant proliferation of synovial lining cells with extension into subsynovial tissue
What is the most common site of pigmented villonodular synovitis?
knee
What are gross findings of pigmented villonodular synovitis?
synovium develops enlarged folds and nodular excrescences
What are microscopic findings of pigmented villonodular synovitis?
1) numerous mononuclear cells
2) pigmented and brown hemosiderin-laden macrophages
3) several multinucleated giant cells
What is nodular tenosynovitis?
“Giant Cell Tumor of Tendon Sheath”; variant of pigmented villonodular synovitis
involves tendon sheath of hands and feet
What is the most common soft tissue tumor of the hands?
Nodular Tenosynovitis
What is treatment of nodular tenosynovitis?
surgery
What is the most common site of nodular tenosynovitis?
flexor surface of middle or index finger
What is Gout and where is it found?
hyperuricemia and the deposition of uric acid crystals in various tissues, primarily the joints, subcutaneous tissue, and kidneys
What is Hyperuricemia?
uric acid >7 mg/dl
Who is most commonly affected by gout?
males with a family history
What is primary gout?
metabolic: hyperproduction of uric acid (most common primary)
renal: underexcretion of uric acid (most common overall)
[most common of all gout]
What is secondary gout?
related to another disease; leukemia, chronic hemolysis, obesity, alcoholism [2/3 of all gout]
What is the general pathology of Gout?
deposits of uric acid crystals in the tissues in the form of insoluble Monosodium Urate; typically develops after many years of asymptomatic hyperuricemia, usually 15-30 years.
Where are the most common sites of deposition?
1) joints [acute]
2) periarticular connective tissue [acute or chronic]
What is the overwhelming first symptom of acute gout?
Tarsometatarsal joint of the big toe. (known as Podagra: foot seizure)
What is a common cause of uric acid release from the joint capsule?
Uric acid is probably released from the deposits in the joint capsule by minor trauma in individuals who are already susceptible. It enters the joint cavity and over-saturates the fluid
What are the signs of acute gout?
all 5 signs of inflammation
What is the best way to diagnose gout?
synovial fluid analysis; polarize and see “needles” of monosodium urate + location
What happens after the uric acid enters into the joint cavity?
promotes crystallization inside the joint due to cold temps; crystals are chemotactic and provide an acute inflammation within the joint
What causes the severe pain in gout?
neutrophils and inflammatory mediators
What else does the crystallization of the uric acid cause in the joint?
activates Complement and Kallikrein, which promotes inflammation and pain, and also recruits more leukocytes into the joint; pain and acute inflammation
How can the clinical features of gout be classified?
acute or chronic; acute: the joint is swollen, hyperemic and warm, and the patient cannot walk; Systemic symptoms include fever, leukocytosis, tachycardia, and general exhaustion. The attacks may last 2-3 days or longer and usually subsides spontaneously
What is distinguishing about chronic gout?
less inflammation, more bone deformities
What is tophi?
subcutaneous deposits of uric acid in gout; most common on the ears, the extensor sites of the arms, over the olecranon, and over the patella; not painful, encapsulated
What are contained within tophi?
1) urate crystals (birefringent) surrounded by: 2) macrophages 3) lymphocytes 4) giant cells
What are the renal complications of gout?
1) renal failure
2) uric acid stones
predispose to:
obstructive nephropathy
chronic pyelonephritis
How do you diagnose gout?
1) hyperuricemia with labs
2) great toe monoarthritic joint pain
3) X-rays to see tophi
What is Pseudogout and where do you find it?
Calcium Pyrophosphate Dihydrate (CPPD) deposition disease refers to the accumulation of this compound in synovial membranes
What is chondrocalcinosis?
deposit in the joint cartilage, ligaments and tendons of pseudogout
What are characteristics of pseudogout?
old age (gout is middle age) preexisting joint damage excessive level of inorganic pyrophosphate in the synovial fluid
Where are the most common places for crystal deposits in pseudogout?
(chondrocalcinosis); knees after trauma and after surgical removal of the meniscu
What other diseases associated with Pseudogout?
1) hyperparathyroidism
2) hypothyroidism
3) hemochromatosis
4) Wilson’s Disease
What are gross findings of pseudogout?
calcium pyrophosphate deposits appear as chalky white areas on the cartilaginous surfaces
What are microscopic findings of pseudogout?
1) crystals of pseudogout are stubby, short, and rhomboid (coffin-shaped)
2) weakly birefringent under polarized light
3) Only a few mononuclear cells and macrophages surround the foci of crystals
What are the clinical features of Pseudogout?
1) self-limited attacks of acute arthritis lasting from 1 day to 4 weeks
2) involve 1 or 2 joints
3) inflammation and swelling of the knees, ankles, wrists, elbows, hips and shoulders (25% patients)
* *no big toe**
In regards to metatarsal joints, how can gout and pseudogout be differentiated?
MT joints spared in pseudogout
In regards to lytic lesions, how can gout and pseudogout be differentiated?
lytic lesions in gout
What are the two main ways to differentiate gout and pseudogout?
1) location
2) crystal type
