Muscculoskeletal, Skin, and Connective Tissue - Pathology

summerahmed's version from 2015-04-28 23:00


Question Answer
McCune-Albright syndromeA form of polyostotic fibrous dysplasia
Multiple unilateral bone lesions assoc w endocrine abnormalities (precocious puberty) and cafe-au-lait spots
Rheumatoid arthritis bone findingsPannus formation (MCP, PIP) (fibrovascular/granulation tissue)
Subcutaneous rheumatoid nodules (fibrinoid necrosis)
Ulnar dev. of fingers
Baker's cyst (in popliteal fossa)
NO DIP Involvement
Markers of RArheumatoid factor (anti-IgG antibody)
anti-cyclic citrullinated peptide antibody
Sjogren's syndrome findings, associations and risksLymphocytic infiltration of exocrine glands, esp lacrimal and salivary
xerophthalmia, xerostomia and arthritis
Parotid enlargement
Dental caries
Anti-SSA (Ro), anti-SSB (La)
↑ risk of B-cell lymphoma
Assoc with RA
Females between 40-60 y/o
Causes of goutLesch-Nyhan syndrome
PRPP excess
↓ excretion of uric acid (thiazide diuretics)
↑ cell turnover
von Gierke's disease
Most often due to underexcretion → hyperuricemia
Gout txAcute: NSAIDs (indomethacin), glucocorticoids
Chronic: xanthine oxidase inhibitors (allopurinol, febuxostat)
Ankylosing spondylitisSeronegative spondyloarthropathy
Chronic inflammatory disease of spine and sacroiliac joints → ankylosis (vertebral fusion), uveitis, aortic regurgitation


Question Answer
SLE presentationsfever, fatigue, weight loss
Libman-sacks endocarditis - verrucous, wart-like, steril vegetations on both sides of valve
hilar adenopathy
Raynaud's phenomenon
Nephritis (common cause of death)
Nephritic - diffuse proliferative glomerulonephritis
nephrotic - membranous glomerulonephritis
Antinuclear antibodies (ANA) (SLE)sensitive, but not specific for SLE
Anti-dsDNA (SLE)very specific, poor prognosis
Anti-Smith antibodies (SLE)very specific, not prognostic
Antihistone antibodies (SLE)more sensitive for drug-induced lupus
Other signs/sxs of SLEMalar rash
Discoid rash - sores that scar, on face
Mucositis (oropharyngeal ulcers)
Serositis (pleuritis, pericarditis)
Sarcoidosis characteristicsimmune-mediated, widespread noncaseating granulomas w elevated serum ACE levels
Black females
Bilateral hilar adenopathy and/or reticular opacities on CXR
Associations w sarcoidosisRestrictive lung disease (interstitial fibrosis)
Erythema nodosum (tender, red nodules on both shins)
Bell's palsy
Epithelial granulomas w microscopic Schaumann and asteroid bodies
Hypercalcemia (d/t elevated 1α-hydroxylase-mediated VitD activation in epithelioid macrophages)
Tx of sarcoidosissteroids
Plymylagia rheumaticaPain/stiffness in shoulders/hips, w fever, malaise, weight loss
No muscular weakkness
Women > 50; assoc w temporal arteritis
↑ ESR, normal CK
Tx: rapid response to low-dose corticosteroids
PolymyositisProgressive symmetric proximal muscle weakness
Endomysial inflammation w CD8 T cells
Involves shoulders
↑ CD, +ANA, + anti-Jo-1 antibodies
Tx: steroids
DermatomyositisProgressive symmetric proximal muscle weakness (similar to polymyositis)
malar rash, Gottron's papules, heliotrope rash, "shawl and face" rash, "mechanic's hands"
&uarr risk of occult malignancy
Perimysial inflammation and atrophy w CD4 T cells
↑ CK, +ANA, +anti-Jo-1 antibodies
Tx: steroids
Myasthenia gravisMost common NMJ disorder
Autoantibodies to postsynaptic ACh receptor
Reversed with AChE inhibitor
Myasthenia gravis presentation and associationsPtosis, diplopia, weakness
worsens with muscle use
Assoc w thymoma, thymic hyperplasia
Lambert-Eaton myasthenic syndromeUncommon
Autoantibodies to presynaptic Ca channel → ↓ ACh release
No help with AChE inhibitor
Lambert-Eaton myasthenic syndrome presentation and associationsProximal muscle weakness
Improves with muscle use
Assoc w small cell lung cancer
Myositis ossificanstrauma → ossification in muscle
SclerodermaExcessive fibrosis and collagen deposition throughout the body
Sclerosis of skin → puffy, taut skin with absence of wrinkles
Most likely cause of death: pulmonary sclerosis
Can also cause sclerosis of renal, cardiovascular, and GI systems
75% females
Diffuse sclerodermaWidespread skin involvement
Rapid progression
Early visceral involvement
Assoc. w Scl-70 antibody (anti-DNA topoisomerase I antibody)
CREST syndromeCalcinosis
Raynaud's phenomenon
Esophageal dysmotility
Telangiectasia - small dilated vessels near the skin or mucous membranes
---limited to skin and face. More benign clinical course---
Assoc w anti-Centromere antibody

Bone tumors

Giant cell tumor (osteoclastoma)Benign
20-40 y/o
Epiphyseal end of long bones (typically distal femur, proximal tibial region)
Locally aggressive beign tumor
"double bubble" or "soap bubble" appearance on xray
Spindle-shaped cells with multinucleated giant cells
Osteochondroma (exostosis)Most common benign tumor
Males <25 y/o
Mature bone with carilaginous cap
Commonly originates from long metaphysis
Osteogenic sarcoma2nd most common 1° malignant bone tumor after multiple myeloma
M>F, 10-20 y/o
Risk factors: Paget's, bone infarcts, radiation, familial retinoblastoma
Occurs at metaphysis of long bones, often around knee region
Codman's triangle (elevation of periosteum) or sunburst pattern on xray
Tx w resection and chemo
Ewing's sarcomaMalignant
Boys < 15y/o
Diaphysis of long bones, pelvis, scapula, and ribs
Anaplastic small blue cell tumor
Extremely aggressive w early mets, but chemo-responsive
"Onion skin" appearance in bone
t(11;22) translocation
Men 30-60 y/o
Pelvis, spine, scapula, humerus, tibia, or femur
Cartilaginous tumor
May be 1° or from osteochondroma
Expansile glistening mass within medullary cavity