Pathoma Flashcards
(56 cards)
Achondroplasia
AD - impaired cartilage proliferation in the growth plate; common cause due to an activating mutation in fibroblast growth factor receptor 3 (FGFR3);
Most mutations are sporadic and related to increased paternal age.
poor endochondral bone formation; intramembranous bone formation is not affected = flat bones = normal head size
Osteogenesis imperfecta
autosomal dominant defect in collagen type 1 synthesis
Clinical features: Multiple fractures, hearing loss, blue sclera—thinning of scleral collagen reveals underlying choroidal veins.
Osteopetrosis
Abnormally thick heavy bone that fractures easily - defect of bone resorption
Carbonic anhydrase II mutation - acid required to remove calcium from bone –> can’t resorb bone
Bone fractures, anemia, thrombocytopenia, leukopenia, vision/hearding impairment (foramen thickening), hydrocephalus, renal tubular acidosis (w/ carbonic anhydrase deficiency).
Treat w/ bone marrow transplant - osteoclasts derived from monocytes
Rickets/osteomalacia
Defective osteoid mineralization - osteoid deposits
Low Vit D levels (resorb Ca and PO4 from intestine)
Rickets - kids <1 year bowing of leg in kids >1
Osteomalacia - weak bone w/ increased risk for fracture
Ca and phosphate decreased, PTH increased, All pos increased
Osteoperosis
Reduced trabecular bone mass –> porous bone w/ increased fracture risk
calcium, phosphate, and PTH are NORMAL vs. osteomalacia
Tx: Exercise, vit D, bisphosphanates - induce osteoclast apoptosis
Osteoblast activation
Increased alkaline phosphatase - need alkaline to lay down calcium.
Paget Dz of bone
Imbalance between osteoblast and osteoclast - localized process 1-2 bones
Osteoclast resorbs excess bone
Results in thick sclerotic bone - osteoblasts try to overcompensate - cement lines between bones - mosaic pattern of lamellar bone
Bone pain (micro fractures), increased hat size, hearing loss, lion-like facies
Isolated alk phos
Tx: Calcitonin (inhibit osteoclasts, opposite of PTH) and bisphosphanates
Complications: osteosarcoma and high-output cardiac output failure
Osteomyelitis
Bacteria in bone - mostly children (seed metaphysis) Adults (seed epiphysis)
S. aureus (most common), pseudomonas (IVDU), TB< pasteurella, N. Gonorrhea, Salmonella (sickle cell)
Bone pain w/ fever + leukocytosis, lytic focus surrounded by sclerosis on X-ray, Dx w/ blood culture
Osteoma
Benign
Surface of facial bones
a/w gardner (familial polyposis, fibromatosis, osteoma)
Osteid osteoma
Benign tumor of osteoblasts - rim of reactive bone
Young adults < 25 years in Cortex of long bones
Bone pain resolves w/ aspirin - bony mass w/ radiolucent core
Osteoblastoma
Benign tumor of osteoblasts
vs. osteoid osteopath - Larger, arises in vertebrae, presents are bone pain that isn’t ASA responsive
Osteochondroma
Benign - Tumor of bone w/ overlying cartilage cap
Cartilage can transform to chondrosarcoma
Osteosarcoma
Malignant osteoblast proliferation - teenagers most common
Risk factors: familial RB
Elederly - paget Dz of bone and radiation increase risk
Metaphysis of long boneDistal femur or proximal tibia
Presents as pathologic fracture, or bone pain and swelling
BX: large pleomorphic cells producing osteoid
Giant cell tumor
Giant cells w/ stroll cells - young adults
In epiphysis - ONLY ONE - Soap bubble on X-ray
Locally aggressive
Ewing sarcoma
Poorlydifferentiated - derived from neuroectoderm
In diaphysis of long bone in young males
Onion skin appearance on X-ray
Easily confused w/ osteomyelitis - fever
(11:22) translocation - chemorpsponsive
Chondroma
Benign - cartilage tumor
Occur in small bones - hands/feet
arises in medulla
Chondrosarcoma
Malignant cartilage tumor
Occur in pelvis/ central skeleton
arises in medulla
Bony metastasis
Most common bone malignancy- mostly osteolytic (punched out)
Prostate cancer is osteoblastic
HLA DR4
Rheumatoid arthritis - synovitis + pannus (inflamed granulation tissue) - DIP spared
Rheumatoid factor - IgM ab against Fc portion of IgG
HLA-B27
seronegative spondyloarthropathies: Psoriatic arthritis, ankylosing spondylitis, and Reiter syndrome
Ankylosing spondylarthritis
sacroiliac joints and spine - male young adults
involvement of vertebral bodies eventually arises, leading to fusion of the vertebrae (‘bamboo spine ).
uveitis and aortitis (leading to aortic regurgitation).
Reiter syndrome
arthritis, urethritis, and conjunctivitis after GI or chlamydia infection (can’t see, can’t pee, can’t climb a tree)
Psoriatic arthritis
In 10% of cases of psoriasis.
Involves axial and peripheral joints; DIP joints of the hands and feet are most commonly affected, leading to “sausage” fingers or toes.
Infectious arthritis
Causes include: N. Gonorrhea— most common, sexually active young adult, S aureus—older children and adults;
single joint, usually the knee, warm with limited range of motion; fever, increased white count, and elevated ESR are often present.
Treat immediately
