Robbins - Joints and ST Tumors (Ch. 26) Flashcards Preview

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Flashcards in Robbins - Joints and ST Tumors (Ch. 26) Deck (60)
1

2 synovial cell types in synovial joints (w/ function)

Type A = phagocytic macrophages

Type B = hyaluronic acid producing fibroblasts

2

Why is hyaline cartilage unique?

No blood supply, no lymphatic drainage, no innervation

3

Composition of hyaline cartilage

Water (70%), Type 2 collagen (10%), proteoglycans (8%), chondrocytes

4

How is articular cartilage destroyed pathologically?

Increased IL-1 and TNF that triggers degradation -- from chondrocytes, synoviocytes, fibroblasts, and inflammatory cells

5

50+, deep achy pain that worsens with use or early morning, crepitus, limited ROM. Muscle spasms, radicular pain, and neurologic deficits

Other name?

What is it?

Osteoarthritis

Degenerative joint disease (DJD)

Degeneration of cartilage and disordered repair that results in structural and functional failure of synovial joints

6

Most common cause of osteoarthritis

It is a disease in which chondrocytes respond to ___ and ___ stresses resulting in the breakdown of the ___

Old age

Biochemical, mechanical
Matrix

7

Men vs. women - most common osteoarthritis locations

Men - Hips
Women - Knees, Hands

8

Early vs. Late OA -- what is happening microscopically?

Early -- chondrocytes proliferate into clusters, water content increases, secrete mediators and proteases that cleave proteoglycans and collagen fibers

Late -- repetitive injury causes chronic inflammation, chondrocyte death, cartilage loss, and subchondral changes

9

OA - see what macroscopically? (3)

Polished ivory surface (eburnation) w/ joint mice (as cartilage is sloughed off) and fibrous-walled cysts

10

Heberden nodes

Bouchard nodes

Seen in what?

Osteophytes at the distal IP joints

Bony outgrowths or cysts of the proximal IP joints

Osteoarthritis

11

Malaise, fatigue, generalized MSK pains. Joints are swollen, warm, painful, and stiff in morning or after inactivity. Joint enlargement and limited ROM.

Most common joints?

Rheumatoid arthritis

Hands and feet, then other extremity joints

12

Progression of RA in the joint?


Damage caused by what mediators?

Complete ankylosis -- fusion of bones, thus near immobility

IL-1, **IL-17 (Th17), TNF, **IFN (Th1)

13

Characteristic exam/radiograph signs for RA (3)

- Radial deviation of wrist
- Ulnar deviation of fingers
- Flexion-hyperextension of fingers (swan-neck)

14

Diagnosing RA (3)

- Classic radiograph findings
- Sterile, turbid synovial fluid w/ decreased viscosity, poor mucin clots, and inclusion-bearing neutrophils
- Rheumatoid factor and anti-CCP antibodies

15

**Synovial cell hyperplasia, dense inflammatory infiltrates, increased vascularity, exudate on joint surfaces, osteoclastic activity

RA

16

**Mass of edematous synovium, germinal centers, inflammatory cells, granulation tissue, and fibroblasts growing over the articular cartilage, causing its erosion

Pannus - RA

17

RA can look like what other diseases? Why?

SLE or scleroderma

Lesions of skin, heart, BVs, and lungs are common as well

18

Molecular findings in RA (2)

Anti-CCP (citrullinated peptides) autoantibodies

Serum IgM or IgA against the Fc portion of serum IgG (Rheumatoid factor)

19

Genetic susceptibility for RA

Other findings in RA (other organs) (2)

HLA-DRB1

Nontender subQ nodules w/ fibrinoid necrosis, small/medium vasculitis

20

Child under 16, arthritis for 6+ weeks

Which joints most common? Few or many?

Molecular finding?
RF? Rh nodules?

Damage done by what?

Juvenile idiopathic arthritis

Large joints - few (oligo)

ANAs
NO RF or nodules

Cytokines (same as RA)

21

Seronegative spondyloarthropathies - what are they?

Immune-mediated diseases (T-cell response), in a susceptible person, to some environmental antigen, that cross reacts w/ native molecules of the MSK system and causes arthritis

22

Seronegative spondyloarthropathies - 4 diseases

Ankylosing spondylitis
Reactive arthritis
Enteritis associated arthritis
Psoriatic arthritis

23

4 commonalities w/ all the seronegative spondyloarthropathies



Why are they termed "seronegative"?

- Pathology of ligamentous attachments of the joint, NOT the synovium
- Sacroiliac joint involvement
- NO RF
- HLA-B27 association

No specific autoantibodies

24

Vertebrae + SI joints
10-20, young males - low back pain, spinal immobility
HLA-B27 (90%)

What is it?

Ankylosing spondyloarthritis

Destruction of articular cartilage and bony ankylosis (fusion)

25

Male, 20-30
Urethritis/cervicitis (non-gonococcal) or bloody diarrhea --> LATER arthritis (joint stiffness, low back pain) and conjunctivitis
HLA-B27 (80%)
Symptoms wax and wane for months

What is it?

Organisms?

Common specific joint findings? (2)

Other complications? (4)

Reactive arthritis (Reiter syndrome)

Autoimmune reaction initiated by the GU/GI infection

Chlamydia or bloody diarrhea GI bacteria (4)

Sausage finger/toe
Calcaneal spurs

Balanitis, conjunctivitis, cardiac arrhythmias, aortic regurgitation

26

30-50, recurrent skin plaques w/ silver scab, joint pains in distal IP joints of hands and feet

Genetic susceptibility?

Common deformity in fingers/toes

How does this arthritis differ from RA?

Psoriatic arthritis

HLA-B27 and HLA-C

Pencil-in-cup deformity


RA = proximal IP joints

27

Infectious arthritis - what is it?

4 types?

Class of arthritis diseases caused by various organisms and infections that seed the joint via hematogenous spread

- Pyogenic
- Mycobacterial (TB)
- Lyme disease
- Viral

28

Sudden, acutely painful and swollen joint w/ restricted ROM. Fever, leukocytosis, and elevated sed rate. Purulent fluid on synovial fluid aspiration. Stains positive for an organism.

Most common organism in...
- Kids
- Adults
- Sickle cell
- Sexually active females

Suppurative (bacterial) arthritis

Kids = H. flu
Adults = staph. aureus
HbSS = Salmonella
Females = Gonococcus

29

Gradually increasing joint (LE) pain, confluent granulomas w/ central caseous necrosis, lung mass or osteomyelitis

Mycobacterial arthritis

30

Hiking in NE US, skin lesion followed later by arthritis of large joint(s) that migrate every 1-2 months. Anti-organism antibody detected in serum.

Organism?

Lyme arthritis

Borrelia burgdorferi

31

Causes of viral arthritis (6)

HIV, HBV, HCV, EBV, Parvo, Rubella

32

30+ male w/ obesity, alcoholic, and/or metabolic syndrome. Transient attacks of acute arthritis w/ redness and warmth in small extremity joint. Dense neutrophilic infiltrate in synovium. Long, slender, needle-shaped crystals found.

Necessary finding on labs?

Common 1st joint?

Gout (acute arthritis)


Hyperuricemia (> 6.8 mg/dL)


BIG TOE

33

MOST causes of hyperuricemia are (known/unknown) and (primary/secondary)

Genetic susceptibility?

Causes of 2º gout? (2)

Unknown, Primary

HGPRT mutation (can't salvage purines)

Chemotherapy (leukemia), Decreased excretion (CKD)

34

Molecular cause of inflammation in gout

MSU crystals --> cytokines and crystal phagocytosis --> proteases and lysosomal enzymes --> injury/inflammation

35

Joints most commonly affected in gout

Why?

Peripheral joints

MSU crystallizes more at lower temperatures

36

Risk factors for gout (5)

- Prolonged hyperuricemia
- HGPRT deficiency (X-linked)
- Heavy alcohol consumption
- Obesity
- Drugs (thiazides) that reduce excretion

37

What happens after many episodes of acute gout?

Chronic tophaceous arthritis...

MSU crystals encrust the articular surfaces, forming visible deposits. Synovium becomes hyperplastic and thickens to form a PANNUS, which leads to articular bone erosions and even bony ANKYLOSIS

38

Large aggregations of urate crystals surrounded by intense inflammatory reaction of foreign body giant cells

When do these form?

Tophi -- hallmark of gout

About 12 years after the initial acute attack

39

Gout - non-arthritic association (chronic)

Nephropathy - nephrolithiasis and pyelonephritis

40

50+, asymptomatic or mild arthritis of upper extremity joint(s), crystals within articular cartilage, menisci, and intervertebral discs. Chalky white, friable deposits seen as oval purple-blue aggregates on staining. Rhomboid, birefringent. NOT NEEDLE-SHAPED.

Other names?

Calcium pyrophosphate crystal deposition (CPPD) disease

Pseudo-gout
Chondrocalcinosis

41

Causes of secondary pseudo-gout (6)

Joint damage
Hyper-PTH
Hypothyroidism
Hemochromatosis
DM
Ochronosis (alkaptonuria)

42

Hereditary form of pseudo-gout

Mutation in pyrophosphate transport channel

43

Most cysts and tumors of the joints are due to ____ to trauma or degenerative processes, NOT ____

Reactivity

NOT primary

44

Small pea-sized firm, fluctuant, translucent nodule in the wrist. Filled w/ synovial fluid. No cellular lining, no connection to the synovial fluid.

Comes via ____

Ganglion cyst

Cystic/myxoid degeneration of connective tissue

45

Herniation of synovium through the joint capsule or enlargement of a bursa, producing a fluctuant mass. Hyperplastic synovial lining w/ inflammatory cells and fibrin.

Most common one?

Synovial cyst


Baker cyst (popliteal - RA)

46

Soft tissue tumors are most likely (benign/malignant)

Benign

47

40-60, well-encapsulated mass on the trunk or proximal extremity. Soft, mobile, painless. Yellow adipose tissue.

Lipoma

48

50-60, poorly differentiated mass in deep tissue of proximal extremity or retroperitoneum. Sheets of anaplastic cells w/ bizarre nuclei and immature adipocytes (lipoblasts).

Genetics?

Pleomorphic liposarcoma

(12;16) FUS-DDIT3

49

50-60, mass in deep tissue of proximal extremity or retroperitoneum. Abundant ground substance and rich capillary network w/ scattered immature adipocytes and primitive round-stellate cells

Genetics?

Myxoid liposarcoma

(12;16) FUS-DDIT3

50

Irregular or nodular thickening of the palmar fascia, w/ puckering and dimpling. 4th and 5th fingers are partially flexed

What is it?

Superficial fibromatosis - Palmar (Dupuytren contracture)

Infiltrative fibroblastic proliferation, causing local deformity

51

Palpable mass on dorsolateral penis. Abnormal curvature of the shaft, difficulty urinating.

What is it?

Superficial fibromatosis - Penile (Peyronie disease)

Infiltrative fibroblastic proliferation, causing local deformity

52

Women 13-30, large poorly-demarcated mass, rubbery and tough, with infiltration of surrounding tissues. Anterior abdominal wall, limb girdle, or mesentery.

Genetics?

Familial disease w/ predisposition?

Deep fibromatosis (Desmoid tumor)

APC or Beta-catenin mutation

FAP (APC mutation)

53

Almost all skeletal muscle tumors are ____

MALIGNANT

54

Child. Infiltrating mass of round and spindle cells in a myxoid stroma. Cells w/ cross striations.

Most common locations?

Embryonal rhabdomyosarcoma


Sinuses, head/neck, GU tract

55

Child, Infiltrating mass of uniform round cells w/ little cytoplasm. Fibrous septae divide the cells into clusters or aggregates. Central cells are discohesive, peripheral cells are adherent to the septae.

Supposed to look like what?

Do NOT see ___

Genetics?

Alveolar rhabdomyosarcoma


Pulmonary alveoli


Cross striations


(1;13) or (2;13) PAX-FOXO1

56

Small, painful nodules in the skin, fascicles of densely eosinophilic spindle cells that intersect at right angles. Blunt-ended, elongated nuclei.

Leiomyoma (of erector pili mm)

57

Painless firm mass in the retroperitoneum or deep extremity. Eosinophilic spindle cells w/ blunt-ended hyperchromatic nuclei in interweaving fascicles. Stains w/ actin-myosin antibodies.

Leiomyosarcoma

58

20-49, deep-seated mass present for several years. Uniform spindle cells w/ scant cytoplasm. Potential gland-like structures w/ cuboidal to columnar epithelioid cells. Keratin-positive (some).

Genetics?

Synovial sarcoma

(x;18) SS18-SSX1/2/4

59

Synovial sarcoma -- usually in the synovium?

NO (misnomer) -- can be joint, chest wall, head/neck

60

Middle age or older. Large mass in deep soft tissue of thigh. Pleomorphic, anaplastic spindle to polygonal cells w/ irregular/bizarre nuclei. Abundant mitotic figures. Lacking differentiation.

Common?

Undifferentiated pleomorphic sarcoma (UPS)

YES - largest category of adult sarcomas