Musculo-Skeletal Pathology

Question 1

Onion-skin periosteal reaction. What disease is associated?

Answer 1

Ewing sarcoma of bone

Question 2

This pathology involves the activation of a fibroblast growth factor receptor that inhibits chondrocyte proliferation (the receptor is always switched on). What is the receptor, and what is the pathology at hand?

Answer 2

Achondroplasia
Receptor: FGFR3
Associated with advanced paternal age and mutations occur sporadically, but IS transmitted AD.

Question 3

This is the MC benign bone tumor, usually seen in young males (<25), where the bone looks like a big bone spur with a cartilage cap on it. Technically a hamartoma (Benign tumor of disorganization of tissue in its normal location). Very low chance of becoming malignant. What pathology is at hand?

Answer 3

Osteochondroma

Question 4

This giant cell tumor is usually seen in Px 20-40yo, and the tumor is located MC on the distal fémur or or the proximal tibia, with a lucid “soap bubble” appearance on XR. It consists of osteoclast involvement.

Answer 4

Osteoclastoma

Question 5

This tumor is the MC malignant bone tumor in children. MC in boys aged 10-20yo, with the MC XR features include Codman’s Triangle (where the tumor pushed up periosteum in the bone, forming a small triangle), and a Sunburst pattern on the bone. (Osteocod in the sun) What pathology is at hand?

Answer 5

Osteosarcoma

Question 6

This malignancy occurs in young boys, aged <15, very aggressive, and tends to grow on the surface of cortical bone (shaft of long bones). XR shows destruction and disruption of the cortex, with an “onion skin” appearance. What is the pathology at hand, and what genetic association is present with this disease?

Answer 6

Ewing Sarcoma —> 11;22 translocation.

Question 7

This disease shows localized disorder of the bony architecture showing increasing osteoblastic and osteoblastic activity resulting in disorganized bone remodeling. A patient will most likely refer increased “hat size” because the bone is getting thicker also referring to loss of hearing (due to thickening of auditory canal), and are at risk for an osteosarcoma. Ca2+, phosphate, and PTH levels are normal, with increased Alk Phos. What pathology is at hand?

Answer 7

Paget Disease of the bone - bone enlargement (head), bone pain, and arthritis

Question 8

What is the triad of McCune-Albright syndrome?

Answer 8

Precocious puberty, Café-au-lait spots, fibrous dysplasia of bone

Question 9

In this disease bone is replaced by fibroblasts, collagen, and irregular bony trabeculae. What disease is at hand?

Answer 9

Polyostotic fibrous dysplasia

Question 10

The patient demonstrates failure of bone resorption causing thickened and dense bones. In addition, there is a genetic deficiency of carbonic anhydrase II. What disease is at hand?

Answer 10

Osteopetrosis

Question 11

Cartilage cells are maintained by chondrocytes, which are derived from the same type of stem cells as adipocytes and osteoblasts. What is their stem cell origin?

Answer 11

Mesenchymal cells from the mesoderm

Question 12

This pathology is the leading cause of knee pain in patients under the age of 45. It typically presents with anterior knee pain that is exacerbated by activity. Treatment involves strengthening the quadriceps, stretching, low stress on the knee, but maximize walking. What pathology is at hand?

Answer 12

Patellofemoral Syndrome

Differential DX- patellar tendinitis: pain upon palpation of the patella.

Question 13

What is the difference between “housemaid knee” (from mopping on your knees), vs “Clergyman’s knee” (where you’re praying all day)?

Answer 13

Housemaid ‘s knee: inflammation of the Prepatellar bursa (prepatellar bursitis)

Clergyman’s knee: inflammation of the infraparellar bursa (infrapatellar bursitis)

Question 14

A 38yo female patient refers pain beneath the calcaneus or in the medial arch, worse with first steps in the morning and after weight bearing exercise. Local point tenderness at the medial tubercle of the calcaneus. +/- heel spur on X-ray.

Answer 14

Plantar fasciitis

Question 15

This pathology involves the contracture of one or more fingers due to a painless thickening and contracture of the flexor tendons of the palm. Usually affects the ring finger or the pinky, but the cause is unknown, may be genetic, aged over 40, being male, alcoholism, diabetes, and smoking. What pathology is at hand?

Answer 15

Dupuytren Contracture

Question 16

What are the major differences between Osteoarthritis and Rheumatoid Arthritis.

Answer 16

Osteoarthritis is wear and tear disease - affects distal IPJ and Proximal IPJ. CF: pain with use.
Rheumatoid arthritis is systemic, and pain is usually in the mornings and improves with use. Also, assoc. w/pannus joints (affecting metacarpal phalangeal joints and proximal IPJ), no DIPs. Also they may present with Baker cysts (cysts behind the knee) and can have swan neck joints (distal IP finger flexion), or Boutonnière joints (distal IP finger extension), fever, fatigue, pleural effusion, pericarditis

Question 17

What are the antibodies for Rheumatoid Arthritis?

Answer 17

(+) Rheumatoid factor is - IgM antibody against IgG (first labeled to rule out RA; patient might be positive with no symptoms at all because of low specificity). If positive though, the confirmatory antibody is:
(+)Anti-citrullinated protein antibody (ACPA) as it is more specific.

Question 18

These diseases increase the chances of developing what disease?

• Lesch-Nyhan Syndrome
• Undergoing treatment for Leukemia or lymphoma
• Use of Thiazides or loop diuretics

Answer 18

Gout

• With increased consumption of purine rich food
• decreased excretion of uric acid (due to diuretic)

Question 19

Px presents with asymmetrical joint inflammation, monoarticular joint pain - MC found at the first metatarsal phalangeal joint (podagra), and presence of tophi in other joints without inflammation. Pain presents in flairs. Negative bi-refringent to polarized light (yellow to parallel polarized light).

Answer 19

Gout

Question 20

What is the MOA of alcohol excretion in the kidney, in relation to Gout?

Answer 20

Alcohol metabolites compete for the same excretion sites as uric acid. The kidney chooses to excrete the alcohol, thus raising levels of uric acid.

Question 21

What is the difference between Gout and pseudo-gout? Where are the crystals MC found?

Answer 21

On the knee and they usually calcify the articulation cartilage- Pseudo-gout is made of Calcium pyrophosphate crystals (rhomboid shaped), and positive bi-refringent (blue, to parallel polarized light and yellow when perpendicular).
UA crystals are yellow to parallel polarized light

Question 22

Seronegative Spondyloarthropathies are associated with what genetic alterations, and what pathologies are involved?

Answer 22

Negative Rheumatoid factor, and strong association with HLA-B27

• Psoriatic arthritis
• Ankylosing spondylitis
• Inflammatory Bowel Disease spondylitis
• Reactive Arthritis

Question 23

This disease is associated w/inflammatory arthritis associated with psoriasis, it presents asymmetrical, involves DIP joints, spine, and sacroiliac joints. CF: sausage fingers with X-ray findings showing “pencil in cup” deformity.

Answer 23

Psoriatic Arthritis

Question 24

This disease is a chronic inflammatory disease that involves the spine and sacroiliac joints. X-ray shows fusion of facet joints, fusion of sacroiliac joints, or fusion of intervertebral discs. Also associated with Uveitis, aortic regurgitation, conduction abnormalities, and CV disease (CHF).

Answer 24

Ankylosing spondylitis (ankylosis = fusion) 
Spondylitis = spine

Question 25

What GI diseases are associated with ankylosing spondylitis and polyarthritis?

Answer 25

Ulcerative colitis, and Crohn’s disease

Question 26

This disease usually follows arthritis post infection - MC: Chlamydia, shigella, salmonella, yersinia, Campylobacter, Clostridium. The patient has an infection, then a reaction to that infection. What is the disease, and the classic triad?

Answer 26

Reactive Arthritis
Triad: conjunctivitis, urethritis, Arthritis
“Can’t see, can’t pee, can’t climb a tree!”

Don’t confuse with septic arthritis where N. Gonorrhea could present similar symptoms.

Question 27

The following arthritis is caused by bacterial infection. CF: Polyaryicular, migratory arthritis, found in a asymmetrical pattern, with pustules on the skin.
Name the 3 MC microorganisms, characteristics, and Dx criteria.

Answer 27

Staph aureus
Streptococcus
Neisseria gonorrhoeae - CC: young Sexually active person that has a painful knee. Findings show Polyarticular, migratory arthritis, in an asymmetrical pattern. Can also cause pustules on the skin, synovitis, and tenosynovitis.

Dx: Arthrocentesis

Question 28

What cardiac abnormality is associated with SLE?

Answer 28

Libman-Sacks endocarditis

—> they look like bacterial vegetations on heart valves, but the are sterile upon culture.

Question 29

What are the diagnostic criteria for Systemic Lupus Erythematosus on the skin?

Answer 29

Skin: Malar rash, discoid rash, photosensitivity, painless oral ulcers.

Question 30

What are the immune system markers associated with SLE?

Answer 30

Could be (+) for ANA (antinuclear antibodies), Antiphospholipid Ab (+), anti-dsDNA, anti-Smith, false (+) VDRL, anti-histone antibodies (+) for drug induced lupus

Question 31

Positive Antinuclear antibodies (positive ANA) sensitivity are all possibilities for what diseases (6)?

Answer 31

Sjögren syndrome
Scleroderma
Polymyositis and dermatomyositis 
Rheumatoid arthritis 
Juvenile idiopathic arthritis 
Mixed connective tissue disease

Question 32

Antiphospholipid (anticardiolipin) antibodies and decreased C3 and C4 are known for what???

Answer 32

Lupus

Question 33

Patient presents with fibrosis and excess collagen deposition found on the skin (tight, shiny with no wrinkles). This type progresses rapidly, involves the visceral organs. What is the disease at hand and the serum marker associated?

Answer 33

Diffuse Scleroderma

-Anti-DNA topoisomerase I (Anti-Scl-70)

Question 34

What are the associations with CREST Syndrome? What is the serum marker for the disease?

Answer 34

Calcinados
Raynaud Phenomenon 
Esophageal dysmotility
Sclerodactyly
Telamgiectasias
*limited skin involvement, less visceral involvement, progress less rapidly, and Anti-centromere antibodies

Question 35

This disease is of muscle inflammation (inflammatory muscle disease) presents with proximal muscle weakness. There is a CD8 T-cell induced injury to the muscle fibers often involving shoulders and pelvic girdle. Dx criteria involves muscle biopsy that shows muscle inflammation. What is the diagnosis and what is seen in blood?

Answer 35

Polymyositis

• Elevated CK
• Elevated Aldolase
• (+) ANA
• (+) anti-Jo-1 antibodies

Question 36

This pathology involves muscle inflammation and skin involvement - malar rash, purple heliotrope rash around eyes, Gottron’s papules on the hands (looks like scale scabs ripped off), and Shawl sign (rash over the shoulders), rough “mechanic hand” type skin on hands or feet. Carries an increased risk of malignancy.

Answer 36

Dermatomyositis

Increased malignancies include general cancers of the population: breast, lung, prostate

Question 37

Excess muscular tenderness in 11 of 18 particular sites trigger points). Or certain generalized symptoms like depression, pain, fatigue, sleep disturbance, anxiety. What is the diagnosis and treatment?

Answer 37

Fibromyalgia
FDA approved TX: Gabapentin and Milnacipran (ssri and snri)
Old tx: Amitriptyline, low dose analgesic, and fluoxetine
And non pharmacological tx like exercise, sleep, reassurance that it’s benign, stress reduction, and stretching

Question 38

What differentiations are there between polymyositis and Polymyalgia Rheumatica?

Answer 38

Polymyositis has muscle pain, where Polymyalgia Rheumatica has joint pain, no muscle pain, no muscle weakness, NORMAL CK, and normal Aldolase.

Question 39

These cell types produce collagen, Glycosaminoglycans, Reticular and elastic fibers, Glycoproteins, and are stimulated by tissue damage. What cell is this?

Answer 39

Fibroblasts

Question 40

These cells are located in the stratum basalis of the epidermis, they originate from neural crest cells and produce melanin.

Answer 40

Melanocytes

Question 41

Compression of ulnar nerve at the wrist causes this pathology. —> cyclist refers numbness and tingling of pinky and ring finger. What pathology is at hand?

Answer 41

Guyon Canal Syndrome

Question 42

What are the diagnostic criteria for SLE on the inflammatory disorders part?

Answer 42

Inflammatory disorders: non erosive Arthritis (2 joints), Serositis, (+)ANA

Question 43

What is the diagnostic criteria for SLE in terms of organ system disorders?

Answer 43

Organ system disorders: Renal (wire loops histology), Neuro, Heme, Immune.

Question 44

What is diagnosis under radiologic imaging for Pseudogout?

Answer 44

Calcification of the meniscus in the knees. Chondrocalcinosis!

Question 45

Pt presents with nystagmus, intention tremor, scanning speech, what is the most likely diagnosis?

Answer 45

Charcot triad of multiple sclerosis

Question 46

What is the difference between Duchenne and Becker Muscular Dystrophy?

Answer 46

Duchenne - X-linked recessive frameshift mutation of dytrophin gene vs. Non- X-linked frameshift deletions in dystrophin (thus Becker has less severe form)