Skeletal system--bone and joints Flashcards

Question

What is the pathology of vit. D deficiencies?

Answer 1

- Decreased bone causes deformities and/or fractures | • Decreased mineralization

Answer 2

Hyperparathyroidism • Parathyroid adenomas most common cause; Parathyroid hyperplasia • Induction of osteoclastic and fibroblastic activity leads to increased resorption of mineral from bone

Answer 3

Irregular, moth-eaten trabecular bone | • ?Brown tumor? – Repeated hemorrhage due to micro-fracture with subsequent fibrosis and macrophage infiltration

Answer 4

Older age: Approximately 3% of population over 50 y.o. affected in U.S. • Cause unknown: Potential viral etiology • Monostotic (localized) form is less common; Polyostotic form approx. 90%

Answer 5

1) Irregular osteoclastic resorption 2) Osteoblastic reformation 3) Osteosclerosis: Late thickening of bone due to net osteoblastic activity

Answer 6

* Haphazard bone architecture: Normal concentric lamellar pattern absent * Highly vascularized bone

Answer 7

Type of neoplasm often affect specific bones or age groups: Differential diagnostic considerations greatly affected by these parameters • Characteristic radiologic features: May be more informative than histology

Answer 8

1) Fibrous dysplasia • Slow replacement of bone by fibroblasts, collagen and irregular bony trabeculae • Monostotic form more common than polyostotic form 2) Aneurysmal bone cyst: Characteristic radiographic appearance; Histology concerning for malignancy

Answer 9

* Exophytic lesions that usually affect skull and facial bones * Usually don?t need treatment * Gardner?s syndrome: Osteomas, GI polyps and soft tissue tumors

Answer 10

Exophytic lesions with prominent cartilaginous caps • Occur on metaphyseal portions of long bones with predilection for bones of hand • Rarely may progress to malignancy

Answer 11

Middle aged patients (20 - 40 y.o.) • Occur in epiphyses of long bones of legs and arms •

Answer 12

* Numerous multinucleated giant cells mixed with small uninucleate cells * Small cells thought to be neoplastic cells * 90% benign/10% malignant * No histologic or other features that allow differentiation of benign from malignant tumors * Development of metastases only sure indicator of malignancy

Answer 13

Affects adolescents and young adults, 10-25 y.o. mostly with involvement of metaphyses of appendiceal bones (femur, humerus, etc.) • Histology characterized presence of osteoid and malignant, anaplastic osteoblasts • Treat with surgery, chemo- and radio-therapy; 60% 5 year survival

Answer 14

``` Older patients (>35 y.o.) with predilection for involvement of central skeleton • Histology characterized by presence of multiple chondrocytes in lacunae with variable degree of atypia • Survival dependent on degree of differentiation ```

Answer 15

Younger age group: Rare after 30 and peak incidence in second decade • Male > female (2:1) • Histology: sheets of uniform small blue cells with syncytial appearance and separated by fibrous septae Cytogenetics: • Translocation 11;22 present in nearly 100% of tumors • PCR assay can be used to establish diagnosis or screen for residual disease Treatment via surgery, chemo- and radio-therapy Prognosis ranges from 45–70% 5 year survival

Answer 16

Pathogenesis • Trauma (wear and tear) and congenital abnormalities are primary influences • Other factors may contribute to small degree – Genetics, osteoporosis Clinical Features • Pauci- or oligo-articular • Large joints (hip, knee) and back are primarily affected • Worse after use (i.e. late in the day) Pathologic features • Cartilage degeneration (loss, fibrillation) with little inflammation • Bone spurs and osteophytes without ankylosis and subchondral cyst formation

Answer 17

Pathogenesis • Autoimmune – Complex lymphocyte and immune complex mediated • Extra-articular disease including rheumatoid nodules, lung disease, etc. • Rheumatoid factor – Serum marker of disease Clinical Features • Multi-articular and usually bilateral/symmetric • Small joints initially (i.e. hand) but may progress to large joints • Worse after inactivity (i.e. in the morning) Pathologic Features • Cartilage destruction with inflammation and pannus form./granulation tissue • Bony and fibrous ankylosis (unlike osteoarthritis)

Answer 18

Clinical/Pathogenesis • Hematogenous (sepsis) or traumatic/direct spread from soft tissue • Pyogenic bacteria (Staph., Strep., Hemophilus, GNRs) or TB • Pathology – Large numbers of neutrophils in the synovial fluid

Answer 19

Clinical/Pathogenesis • Hyperuricemia (renal dis., overproduction) leads to deposits in joints • Big toe (classic site) and others (knee, etc) can be involved • Other crystal arthropathies also occur (pseudogout – Ca pyrophosphate) • Pathology – Crystals (& neutrophils) with specific polarization characteristics in synovial fluid and gouty tophi (deposits in soft tissues)

Answer 20

Exophytic lesions with prominent cartilaginous caps Occur on metaphyseal portions of long bones with predilection for AROUND THE KNEWW Rarely may progress to malignancy

Answer 21

Benign cartilage tumor arising in medullary cavity of bone | Metaphyseal lesion of tubular bones, especially of hands and feet