Musculoskeletal Pathology

1. Hyperthyroidism: benign adenoma, Brown tumors, Salt & Pepper skin, inc. serum calcium

2. Metabolic

2.1. Rickets: Vit D dec. in children, rachitic rosary

2.2. Secondary Osteoporosis: Cushing's, dec. vitamin C/D

3. Neoplastic (Malignant)

3.1. Multiple Myeloma: Most common malignant bone tumor, rain drop appearance (skull), reverse AG ratio

3.2. Osteomalacia: Looser's zones, low calcium serum, dec. vitamin D in adults

3.3. Osteosarcoma: #1 in children & teens, sunburst appearance, Codman's Triangle

3.4. Chondrosarcoma: cartilaginous, P53 oncogene on Chromosome 17, pain worse at night, speckled calcification

3.5. Ewing's sarcoma: 2nd m/c in children, onion skin appearance

3.6. Skeletal metastases: breast 70%, lung 25%, prostate 60%

4. Joint Diseases

4.1. Degenerative Joint Disease: primary- age related (Heberden & Bouchard nodes) secondary- previous joint trauma

4.2. Rheumatoid Arthritis: HLA DR4 marker, small joints, swan neck deformity, Bouchard & Haygarth nodes

4.3. Enteropathic Arthritis: bowel disease, large joints

4.4. Ankylosing Spondylitis: males, SI joint tenderness, Bamboo spine, dagger sign

4.5. Gout: high purine tophi, podagra

4.6. Reiter's Syndrome: males, chlamydia or shigella

4.7. Pseudo-gout: knee, chondrocalcinosis

4.8. Myasthenia gravis: autoimmune, bilateral ptosis & diplopia

4.9. Lambert- Eaton Syndrome: paraneoplastic, bilateral ptosis, neg. Tensilon test

4.10. Polymyositis: autoimmune, skeletal muscle destroyed

4.11. Dermatomyositis: autoimmune, Gottron's papules

4.12. Psoriatic Arthritis: HLA B27, small joints, pitted nails, sausage fingers

5. Miscellaneous

5.1. Muscle Tumors: leiomyoma & leiomyosarcoma, rhabdomyoma & rhabdomyosarcoma

5.2. Slipped Capital Femoral Epiphysis: possible Salter- Harris type 1, disruption of Klein's line

5.3. Salter-Harris Fractures (1-5)

5.4. Legg- Calve' Perthes Disease: avascular necrosis, head of femur

6. Osetomyelitis: Staph. aureus (normal), salmonella (Sickle cell), Brodie abscess, sequestrum involecrum

6.1. Achondroplasia: Autosomal Dominant, FGFr, Champagne-glass appearance

7. Developmental

7.1. Osteoporosis: dec. bone mass, primary, post menopausal

7.2. Osteopetrosis: Osteoclast dysfunction, thick brittle bones, anemia, leukopenia

7.3. Osteogenesis Imperfecta: Type I collagen, blue sclera, malformed teeth, inc. bone fracture in infants

8. Infectious

8.1. Paget's Disease: Paramyxo virus, mosaic laminal bone, cotton wool appearance

9. Neoplastic (Benign)

9.1. Osteoid Osteoma: small benign <2cm, metaphysis & diaphysis, bone pain at night relieved by aspirin

9.2. Osteoblastoma: benign, >2cm, metaphysis & diaphysis

9.3. Osteochondroma: benign, cartilage, exostosis, cauliflower, coat-hanger

9.4. Osteoma: endostosis, bone surface, skull/facial, bone island

9.5. Multiple Enchondroma: Oiler's Disease, hand, Mafffucci's Syndrome

9.6. Vertebral Hemaangioma: most common benign bone tumor of the spine, sand-dollar appearance

9.7. Aneurysmal Bone Cyst: Eccentric, benign, metaphysis, can travel into epiphyseal plate, soap bubble

9.8. Chondroblastoma: benign epiphysis, most common in males, lytic lesions

9.9. Giant Cell Tumor: benign, epiphysis to metaphysis, soap bubble appearance

9.10. Chondroma: benign, cartilage, single/multiple spotty calcifications, epiphysis