MSK/ Derm pathology Flashcards
- repetitive flexion (forehand shot) causing pain near epicondyle
- repetitive extension (backhand shot) causing pain near lateral epicondyle
- medial epicondylitis
- lateral epicondylitis
boxer’s fracture, commonly caused by direct impact with closed fist (punching a wall)
seen in 4th and 5th metacarpals
metacarpal neck fracture
entrapment of median nerve in carpal tunnel (between transverse carpal ligament and carpal bones) –> nerve compression–> paresthesia, pain, and numbness in distribution of median nerve
patient comes in with thenar eminence atrophies but sensation spared, because palmar cutaneous branch enters hand external to carpal tunnel
positive tinel sign sign and phalen maneuver
associated with pregnancies (due to edema), RA, hypothyroidism, diabetes, acromegaly, dialysis-related mayloidosis; may be associated with repeitive use
carpal tunnel syndrome
compression of ulnar nerve twist. classically seen in cyclist due to pressure from handlebar
Guyon canal syndrome (both the ulnar nerve and ulnar artery runs through the Guyon canal)
inflammation of the gluteal tendon and bursa lateral to greater trochanter of femue.
treatment with NSAID, heats, and stretching
trochanteric bursitis
common injury in contact sport due to lateral force applied to planted foot. consost of damage to the ACL, MCL, and medial meniscus (attached to the MCL)
however, lateral meniscus involvement is most common than medial meniscus involvement in conjunction with ACL and MCL injury. presents with acute knee pain and signs of joint injury/instability
this is the unhappy triad
inflammation of the prepatellar bursa in front of the knee cap due to repeated trauma or pressure from excessive kneeling (housemaid’s knee)
prepatellar bursitis
popliteal fluid collection in gastrocnemius-semimembranosus bursa commonly communicating with synovial space and related to chronic joint disease (osteoarthritis and rheumatoid arthritis)
baker cyst
non-inflammatory thickening of abductor pollicis longus and extensor pollicis brevis tendons characterized by pain or tenderness at radial styloid.
positive Finkelstein test (pain at radial styloid with active or passive stretch of thumb tendons). risk in new mothers, golfers, racquet sport players
De Quervain tenosynovitis
fluid-filled swelling overlying joint or tendon sheath, most commonly at dorsal side of wrist. Arises from herination of dense connective tissue
ganglion cyst
overuse injury of lateral knee that occurs primarily in runners. pain develops secondary to friction of iliotibial band against lateral femoral epicondyle
iliotibial band syndrome
increase pressure within fascial compartment of limb (defined by pressure different of 30mmHg or less between the tissue compartment pressure and distolic blood pressure)–> venous outflow obstruction and arteriolar collapse–> anoxia and necrosis.
causes include significant long bone fractures, reperfusion injury, animal venoms
present with severe pain and tense, swollen compartments with limb flexion. motor deficits are late sign of irreversible muscle and nerve damage
limb compartment syndrome
also called shin splints. common cause of shin pain and diffuse tenderness in runners and military recruits. caused by bone resorption that outpaces bone formation in tibial cortex
medial tibial stress syndrome
inflammation of plantar aponeurosis characterized by hell pain (worse with first steps in the morning or after period inactivity) and tenderness.
plantar fasciitis
abnormal acetabulum development in newborns. result in hip instability/dislocation. commonly tested with ortolani and barlow maneuvers (reveal “clunk”)
confirmed via ultrasound (x-ray not used until 4-6 months because cartilage is not ossified)
treatment: splint/harness
developmental dysplasia of the hip
idiopathic avascular necrosis of femoral head. commonly presents between 5-7 years with insidious onst of hip pain that may cause child to limp. more common in males
initial xray is normal
Legg-Calve-Perthes disease
overuse injury casued by reptitive strain and chronic avulsion of secondary ossification center of proximal tibial tubercule. occurs in adolescents after growth spur.
common in running and jumping athletes. presents with progressive anterior knee pain
overuse injury that commonly presents in young, female athetes as anterior knee pain.
exaberbated by prologed sitting or weight-bearing on flexed knee.
Tx: NSAIDs, thigh muscle strengthening
patellofemoral syndrome
also called nursemaid’s elbow
common elbow injury in children <5 yo. caused by sudden pull on arm–> immature annular ligament slips over head of radius.
injured arm held in extended/slightly flexed and pronated position
radial head subluxation
classically present in an obese (12yo) child with hip/knee pain and altered gait. increased axial force on femoral head–> epiphysis displaces relative to femoral neck (like a scoop od ice cream slipping off a cone)
dx with xray and tx with surgery
slipped capital femoral epiphysis
incomplete fracture extending partway through width of bone following bending stress; bone fails on tension side; compression side intact (compar to torus fracture). bone is bent like a green twig
greenstick fracture
axial force applied to immature bone–> cortex buckles on compression (concave) side and fractures.
Tension (convex) side remains solid (intact)
torus (buckle) fracture
failure of longitudinal bone growth (endochondral ossification)–> short limbs, membransous ossification is not affected–> large head relative to limbs
constitutive activation of fibroblast growth factor (FGFR3) actually inhibits chroncyte proliferation. >85% of mutations occur sporadically; autosomal dominant with full penetrance (homozygosity is lethal)
associated with increase paternal age
most common cause of short limbed dwarfism
achondroplasia
trabecular (spongy) and cortical bone lose mass and interconnections despite normal bone mineralization and lab values (serum Ca and PO4)
most commonly due to increase bone resorption related to decreased estrogen and old age,
secondary to drugs (steroids, alcohol, anticonvulsantsm anticoagulant, thyroid replacement therapy)
other condition (hyperparathyroidism, hyperthyroidism, muliple myeloma, malabsorption syndrome)
DEXA at lumbar spine, total hip, femoral neck, with T score of < 2.5 or by fragility fractures. (fall from standing height, minimal trauma) at hip or vertebra.
one time screening recommended in women > 65 yo
Tx: bisphosphonate, teriparatide, SERMs, rarly calcitonin, denosumab (monoclonal antibody against RANKL
failure of normal bone resorption due to defective osteoclast–> thickened, dense bones that are prone to fracture, mutation (carbonic anhydrase 2) impair ability of osteoclast to generate acidic environment neccessary bone resorption. overgrowth of cortical bone fills marrow space–> pancytopenia, extramedullary hematopoeisis
can result in cranial nerve impingment and palsies due to narrowed foramina
xray- show diffuse symmeteric sclerosis (bone-in-bone) “stone bone”. bone marrow transplant is potentially curative as osteoclast ferived from monocytes
osteopetrosis
defective mineralization of osteoid (osteomalacia) or cartiliaginous growth plates (rickets)
most commonly due to vitamin D deficiency
xray: osteopenia and looser zones (psuedofractures) in osteomalacia. epiphyseal widening and metaphyseal cupping/fraying in rickets
childrens with rickets have pathologic bow legs, bead-like costochondral junctions (rachitic rosary), craniotabes (soft skull)
decrease vit D–> decrease Ca–> increase PTH secretion –> decrease serum PO4
hyperactivity of osteoblast–> increase alkaline phosphotases
osteomalacia/rickets
aka Paget disease of bone . common, localized disorder of bone remodeling caused by osteoclastic activity followed by increase osteoblastic activity that form poorly formed bones
serum Ca, phosphorus, and PTH levels are normal.
increase ALP
mosaic pattern of woven and lamellar bone (osteocytes within lacunae in choatic juxtapositions); long bones chalk-stick fractures. increase blood flow from increase arteriovenous shunt may cause high-output heart failure
increase risk of osteosarcoma
hat size can increased (skull thickening), hearing loss is common due to auditory foramen narrowing
stages of Paget disease:
Lytic-osteoclasts
mixed-osteoclast + osteoblast
sclerotic-osteoclast
quiescent-minimal osteoclast/osteoblast activity
tx with bisphosphonates
Osteitis deformans
avascular necrosis of bone
femoral head is the most common site of infarction (watershed zone ) due to insufficiency medial circumflex femoral artery)
corticosteroids, alcoholism, sickle cell, trauma, SLE, Legg-Clave-Perhes disease, Gaucher disease, slipped capital femoral epiphysis
components
Disorder, serum Ca, PO4, ALP, PTH, comments
Osteoporosis-same in all, decrease bone mass
osteopetrosis-decrease serum Ca or same, rest are the same, dense, brittle bone, Ca decrease in severe case, malignant disease
paget disease of bone- increase ALP, same in rest, abnormal “mosaic” bone architecture”
osteitis fibrosa cystica ( and primary hyperparathyroidism)-PO4 decrease, increase in rest, brown tumors due to fibrous replacement of bone, subperiosteal thinning
secondary hyperparathyroidism-decrease Ca, increase in rest, compensation for CKD (decrease PO4 excretion and production of activated vit D)
Osteomalacia/rickets- decrease in Ca and PO4, increased in rest, soft bones, vitamin D deficiency also causes secondary hyperparathyroidism
Hypervitaminosis D- increase Ca, PO4, decrease PTH, same ALP, caused by oversupplementation or granulomatous disease (sarcoidosis)
primary bone tumors (benign)
components in this order
Osteochondroma-most common in male <25yo, located: metaphysis of long bones characterized: lateral bony projection of growth plate (continous with marrow space) covered by cartilaginous cap. rarely transform to chondrosarcoma
Osteoma- middle age, located: surface of facial bones, characterized: associated with Gardner syndrome
Osteoid osteoma-adults <25, male > female located: cortex of long bones, characterized: presents as bone pain (worse at night) that relieved by NSAIDs, bony mass (<2cm) with radiolucent osteoid core
Osteoblastoma- male> female, located: Vertebrae, characterized: similar histolgy to osteoid osteoma. larger size (>2cm), pain unresponsive to NSAIDs
Chondroma-located in medulla of small bones of hand and feet, characterized by benign cartilage
giant cell tumor- 20-40 yo, located epiphysis of long bones (often in knee region), characterized: locally aggressive benign tumor. Neoplastic mononuclear cells that express RANKL and reactive multinucleated giant (osteoclast-like) cell “osteoclastoma. “soap bubble” apperance on xray
malignant tumors
osteosarcoma (osteogenic sarcoma) <20yo males, less common in elderly, located: metaphysis of long bones (often in knee region), characteristic: pleomorphic osteoid-producing cells (malignant osteoblasts), presnts as painful enlarging mass or pathologic fractures, Coman triangle (from elevated periosteum) or sunburnt pattern on xray.
predisposing factors: paget disease of bone, bone infarcts, radiation, familial retinoblastoma, Li-Fraumeni syndrome
Chondrosarcoma: located: medulla of pelvis, proximal femur and humerus, characterized: tumor of malignant chondrocytes
Ewing sarcoma-most common in caucasians. generally in boy < 15 years, located: diaphysis of long bones (femur), pelvic and flat bones, characterized: anaplastic small blue bells of neuroectodermal origin, t(11;22)-fusion of EWS-FLI1, onion-skin periosteal reaction in bone, aggressive with early metastatases
Osteoarthritis-mechanical -wear and tear destroys articular cartilage (degenerative joint disorder)–> inflammation with inadequate repair. Chondrocytes mediate degradation and inadequate repair, presentation: pain in weight-bearing joints after use (end of the day), improved with rest. asymmetrical joint involvement. knee cartilage loss begins medially (bowlegged) no systemic symtpoms, Joint finding: osteophytes (bone spurs) joint space narrowing subcondral sclerosis and cyst. synovial fluid noninflammatory (WBC < 2000) development of Heberden nodes-high, involves DIP, Bouchard nodes (below, involves PIP) and 1st CMC, not MCP, treatment: activity modification, acetaminophen, NSAIDs, intra-artcular glucocorticoids
predisposing: age, female, obesity, joint trauma
Rheumatoid arthritis- autoimmune inflammation induces formation of pannus (proliferative granulation tissue) which erodes articular cartilage and bone, presentation: erosion, juxta-articular osteopenia, soft tissue swelling, subchondra; cyst, joint space narrowing. deformities: cervial subluxation, ulnar finger deviation, swan neck, boutonniere-deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension)., involves PIP, MCP, wrist, not DIP or CMC. synovial fluid inflammatory, Treatment: NSAIDs, steroids, methotrexate, sulfasalazine, hydroxyxhloroquine, leftunomide), biologic agent (TNF-alpha inhibitor)
predisposing: HLA-DR4, positive RF, symetrical joint involvement
extraarticular manifestation: rheumatoid nodules (fibrinoid necrosis with palisading histiocytes) in subcutaneous tissue and lung (positive pneumoconiosis–> Caplan syndrome) interstitial lung disease, pleuritis, pericarditis, anemia of chronic disease, neutropenia + spenomegaly (Felty syndrome) AA amyloidosis, Sjogren syndrome, scleritis, carpal tunnel syndrome
inflammation of monoarthritis caused by precipitation of monosodium urate crystal in joints
- underexcretion of uric acid-largely idiopathic, potentiated by renal failurem exacerbated by thiazide and diuretics
2. overproduction of uric acid: lesch-Nyhan syndrome, PRPP excess, increase cell turnover (tumor lysis syndrome, von Gierke disease
crystals are needle shaped and negative birefringent under polarized light (yellow under parallel light, blue under perpendicular light) serum uric acid can be normal in acute gout.
sx: asymmetric joint distribution, joint swollenm red, painful. (MTP of big toe aka podagra), tophus formation (in external ear, olcranon bursa, achilles tendon), attack tends to occur after large meals with food rich in purines (red meat and seafood), dehydration, alcohol consumption (alcohol competes for same excretion site as uric acid.
treatment with NSAIDs (indomethacin) , steroids, colchicine. chronic: preventive: xanthine oxidase inhibitor (allopurinol, febuxostat)
Gout
aka pseudogout. deposition of calcium pyrophosphate crystals within the joint space. occurs in patients > 50 yo; both sex affected equally
associated with hemochromatosis, hyperthhyroidism, joint trauma
pain and swelling with acute inflammation (pseudogout) and chronic degeneration (psuedo-osteoarthritis). knee most commonly affect joint
chondrocalcinosis (cartilage calcification) on xray
crystals are rhomboid and weakly positive birfringent under polarized light (blue when parallel to light)
acute treatment: NSAIDs, colchicine, steroids
prophylaxis: colchicine
calcium pyrophosphate deposition
systemic juvenile idiopathic arthritis
systemic arthritis seen in < 12 yo presents with daily feverm salmon-pink macular rashm arthritis (commonly 2+ joints) frequently presents with leukocytosism thrombocytosis, anemia : icnrease ESR, CRP,treatment: NSAIDs, steroids, methotreaxtae, TNF inhibitor
autoimmune disorder characterized by destruction of exocrine glands (especially lacrimal and salivary) by lymphocytic infiltrates
40-60yo
Findings:
. Inflammatory joint pain
. Keratoconjunctivitis sicca (tear production
and subsequent corneal damage)
. Xerostomia ( saliva production B )
. Presence of antinuclear antibodies,
rheumatoid factor (can be in the absence of
rheumatoid arthritis),
antiribonucleoprotein
antibodies: SS-A (anti-Ro) and/or SS-B (anti-
La)
. Bilateral parotid enlargement
Anti-SSA and anti-SSB may also be seen in
SLE. ⊕ Anti-SSA in pregnant women with
SLE –> increase risk of congenital heart block in the
newborn.
A common 1’ disorder or a 2’ syndrome
associated with other autoimmune disorders
(eg, rheumatoid arthritis, SLE, systemic sclerosis).
Complications: dental caries; mucosa-associated
lymphoid tissue (MALT) lymphoma (may
present as parotid enlargement).
Focal lymphocytic sialadenitis on labial salivary
gland biopsy can confirm diagnosis.
Septic arthritis
picture: A. lymphocytic infiltrates. B) xerostomia (decrease saliva production) –> mucosal atrophy, fissuring of the tongue
S aureus, Streptococcus, and Neisseria gonorrhoeae are common causes. Affected joint is swollen,
red, and painful. Synovial fluid purulent (WBC > 50,000/mm3).
Gonococcal arthritis—STI that presents as either purulent arthritis (eg, knee) or triad of
polyarthralgia, tenosynovitis (eg, hand), dermatitis (eg, pustules).
septic arthritis
Arthritis without rheumatoid factor (no anti-IgG antibody). Strong association with HLA-B27
(MHC class I serotype). Subtypes (PAIR ) share variable occurrence of inflammatory back
pain (associated with morning stiffness, improves with exercise), peripheral arthritis, enthesitis
(inflamed insertion sites of tendons, eg, Achilles), dactylitis (“sausage fingers”), uveitis.
- Psoriatic arthritis
2. Ankylosing spondylitis
3. Inflammatory bowel disease
4. Reactive arthritis
Psoriatic arthritis
Associated with skin psoriasis and nail lesions.
Asymmetric and patchy involvement A .
Dactylitis and “pencil-in-cup” deformity of
DIP on x-ray (C).
Ankylosing spondylitis
Symmetric involvement of spine and sacroiliac
joints –> ankylosis (joint fusion), uveitis, aortic
regurgitation.
Bamboo spine (vertebral fusion) (C) . Can cause restrictive lung disease due to limited chest wall expansion (costovertebral and costosternal ankylosis).
More common in males.
Inflammatory bowel disease
Crohn disease and ulcerative colitis are often
associated with spondyloarthritis.
Reactive arthritis Formerly known as Reiter syndrome.
Classic triad:
.Conjunctivitis
.Urethritis
. Arthritis
Shigella, Yersinia, Chlamydia, Campylobacter,
Salmonella (ShY ChiCS).
Systemic lupus erythematosus
Systemic, remitting, and relapsing autoimmune disease. Organ damage primarily due to a type III
hypersensitivity reaction and, to a lesser degree, a type II hypersensitivity reaction. Associated with
deficiency of early complement proteins (eg, C1q, C4, C2) –> decrease clearance of of immune complexes.
Classic presentation: rash, joint pain, and fever in a female of reproductive age (especially of
African-American or Hispanic descent).
Libman-Sacks Endocarditis—nonbacterial, verrucous thrombi usually on mitral or aortic valve and can be present on either surface of the valve (but usually on undersurface). LSE in SLE.
Lupus nephritis (glomerular deposition of DNA-anti-DNA immune complexes) can be nephritic or nephrotic (causing hematuria or
proteinuria). Most common and severe type is diffuse proliferative.
Common causes of death in SLE: Renal disease
(most common)
Rash (malar A or discoid B )
Arthritis (nonerosive)
Serositis (eg, pleuritis, pericarditis)
Hematologic disorders (eg, cytopenias)
Oral/nasopharyngeal ulcers (usually painless)
Renal disease
Photosensitivity
Antinuclear antibodies
Immunologic disorder (anti-dsDNA, anti-Sm,
antiphospholipid)
Neurologic disorders (eg, seizures, psychosis)
pregnancy with positive anti-SSA can have newborn with neonatal lupus (congenital heart block, periorbital/diffusion, rash, transaminitis, cytopenias at birth
increased CK, ⊕ ANA (nonspecific), ⊕ anti-Jo-1 (histidyl-tRNA synthetase) (specific), ⊕ anti-SRP (specific), ⊕ anti-Mi-2 (specific) antibodies.
Both disorders associated with interstitial lung disease.
Treatment: steroids followed by long-term immunosuppressant therapy (eg, methotrexate).
Polymyositis: Progressive symmetric proximal muscle weakness, characterized by endomysial inflammation with CD8+ T cells. Most often involves shoulders.
dermatomyositis: Clinically similar to polymyositis, but also involves malar rash (similar to that in SLE but involves nasolabial folds), Gottron papules A , heliotrope (violaceous periorbital) rash B , “shawl and face” rash C , darkening and thickening of fingertips and sides resulting in irregular, “dirty”-appearing
marks.
increase risk of occult malignancy. Perimysial inflammation and atrophy with CD4+ T cells.
Myastenia gravis- most common NMJ disorder due to autoantibodies to postsynatpic ACh receptor, clinical: ptosis, diplopia, weakness (respiratory muscle involvement–> dyspnea. bulbar muscles–> dysphagia, difficulty chewing), worse with muscle use. treatment: AChE inhbitor: reverse sx
associated with thymoma, thymic hyperplasia
Lambert-Eaton myastenic syndrome-uncommon, autoantibodies to presynaptic Ca channel to lower ACh release, clinical: proximal muscle weakness, autonomic symptoms (dry mouth, impotence) improves with muscle use
AChE inhibitor have miminal effects
associated with small cell lung cancer
Triad of 1. autoimmunity, 2. noninflammatory vasculopathy, and 3. collagen deposition with fibrosis.
Commonly sclerosis of skin, manifesting as puffy, taut skin (A)without wrinkles, fingertip pitting
(B). Can involve other systems, eg, renal (scleroderma renal crisis; treat with ACE inhibitors),
pulmonary (interstitial fibrosis, pulmonary HTN), GI (esophageal dysmotility and reflux),
cardiovascular. 75% female. 2 major types:
. Diffuse scleroderma —widespread skin involvement, rapid progression, early visceral
involvement. Associated with anti-Scl-70 antibody (anti-DNA topoisomerase I antibody).
. Limited scleroderma —limited skin involvement confined to fingers and face. Also with CREST syndrome: Calcinosis cutis (C) , anti-Centromere antibody, Raynaud phenomenon,
Esophageal dysmotility, Sclerodactyly, and Telangiectasia. More benign clinical course.
scleroderma
