Flashcards in Pathoma: Skeletal System Deck (55):
What is achondroplasia?
impaired proliferation on the growth plate...dwarfism
Genetic mutation cause of achondopliasia?
Activating mutation in fibroblast growth factor receptor 3 (FGFR3)
Process of endochondrial bone formation?
Formation of cartilage matrix which is then replaced by bone
Process of intramembranous bone formation?
Bone formation without preexisting cartilage matrix
What are the clinical features of someone with achondroplasia?
Short extremities with normal sized head and chest
Normal mental function, lifespan and fertility
What is osteogenesis imperfecta?
Congenital defect of bone formation resulting in structurally weak bone
What is the mutation found in osteogenesis imperfecta?
Collagen type I mutation
Is the OI mutation usually AR, AD, or x linked?
Clinical features of OI?
Multiple fractures of bone
What is osteopetrosis?
Inherited defect of bone resorption...thick, heavy bone that fractures easily
Which type of cells are poorly functioning in osteopetrosis?
Clinical features of osteopetrosis?
Bone fractures, bone marrow under production, extramedullary hematopoiesis, vision and hearing impairment, hydrocephalus, renal tubular acidosis
Why is there renal tubular acidosis in osteopetrosis?
because it is associated with a CA II mutation (which decreases reabsorption of bicarb and results in a metabolic acidosis)
What is the defect in rickets or osteomalacia?
Defective mineralization of osteoid
Which cells produce osteoid?
What is the main cause of rickets or osteomalacia?
low vit D--> low Ca and PO4
What are the 3 main actions of vitamin D?
Increase intestinal absorption of Ca and PO4
Increase renal reabsorption of Ca and PO4
Increase bone resporption of Ca and PO4
What are the lab findings in osteomalacia?
(Ca, PO4, PTH, alkaline phosphate)
When does someone have their peak bone mass?
What is osteoporosis?
reduction in trabecular bone mass leading to porous bones with an increased risk of fracture
What is Paget disease of the Bone?
Imbalance between osteoblast and osteoclast function
THICK, SCLEROTIC BONE that fractures easily
What are the 3 clinical stages of paget disease of the bone?
Mixed osteoblastic- osteclastic
What is the histology pattern in Paget disease on biopsy?
Mosaic pattern of lamellar bone
What are the clinical features of Paget disease?
Bone pain, increasing hat size, hearing loss, lion-like facies, isolated elevated alkaline phosphatase
What is the treatment for pagets?
Calcitonin and bisphosphonates
What is osteomyelitis?
Infection of marrow and bone
What is the main organism that causes osteomyelitis?
Osteomeylitis in sexually active young adults?
Osteomyelitis in sickle cell disease?
Osteomyelitis in diabetic or IV drug users?
Osteomyelitis in dog/ cat bites?
Name a benign tumor of bone associated with facial bones and Gardener Syndrome?
Name a benign tumor of osteoblasts that are surrounded by reactive bone in the cortex of long bones with paint hat resolves with aspirin
Benign tumor of osteoblasts, surrounded by reactive bone that arises in vertebrae and is not responsive to aspirin?
What is a tumor of bone with an overlying cartilage cap?
malignant proliferation of osteoblasts
Risk factors of osteosarcoma?
retinoblastoma, paget disease, radiation exposure
Where in the bone does osteosarcoma usually form?
metaphysis of long bones ( in the knee region usually)
Imaging for osteosarcoma reveals...
destructive mas with a sunburst appearance
What is a tumor comprised of multinucleated giant cells and stroma cells that arise in epiphysis of long bones?
giant cell tumor
Appearance of giant cell tumors on imaging?
What is a malignant prolifeation of porly differentiated cells derved from neuroectoderm that is in the diaphysis of long bones
What age is Ewing sarcoma usually seen in?
Which cancer has a t(11;22) translocation?
Appearance of Ewing sarcoma on xray?
What is a benign tumor of cartilage that arises in the medullary of small bones of HANDS and FEET?
What is a malignant cartilage forming tumor that arise in the medulla of pelvis or central skeleton?
What is the most common tumor in bone/ cartilage?
Metastatic tumors....you see osteolytic lesions
What is a benign tumor or adipose tissue?
What is a malignant tumor of adipose tissue?
Lipoblast is the characteristic cell of...
What is a benign tumor of skeletal muscle?
What is a malignant tumor of skeletal muscle?
Rhabdoblast is the characteristic cell of...