skeletal system: metabolic and neoplastic diseases

metabolic disease

a disease that disrupts normal functions of the body

osteoporosis (sub)

• The structural integrity of the trabecular bone pattern is destroyed. Porous and brittle bone

• It is identified as a bone mass less than 648 mg/cm².

• Major cause of hip, spine, and wrist fractures in women over  50.

osteopenia

• A radiographically visible decrease in bone density

• Occurs as a result of osteoporosis or osteomalacia.

• Identified as a bone mass between 648 and 833 mg/cm².

primary osteoporosis

• Postmenopausal is the most common form of this type of osteo

  • caused by a lack of estrogen which weakens the bone matrix

• Senile

secondary osteoporosis

• Most commonly associated with an existing disease process:

  • Endocrine diseases

  • Neoplastic diseases

  • Malnutrition

  • Chronic renal failure

  • Hereditary diseases

-Or as a result of drug therapy.

osteomalacia (sub)

• Caused by lack of calcium in tissues and failure of bone tissue to calcify.

• Results from inadequate intake or absorption of vitamin D.

rickets

Termed used if osteomalacia occurs before growth plate closure. happens in kids

osteomalacia xray

• Appears similar to osteoporosis.

• Bowing and greenstick fractures

Paget’s Disease (sub and des)

• Fairly common in the older population.

• cause is unknown

• Usually begins in the 5^th decade of life.

• Can affect one or more bones.

• Most common in the pelvis, spine, skull, and long bones.

two stages of paget’s disease

1.  Osteolytic Stage: Bone undergoes continuous destruction.

1. Osteoblastic Stage: bone replaced by abnormally soft and poorly mineralized material. It is thicker than the normal bone, and adds weight and more stress to the bone which causes deformities and fractures.

paget’s disease xray

cotton wool appearance

acromegaly (add)

• An endocrine disorder caused by a disturbance in the function of the pituitary gland.

• More common in females than males.

• Caused by excessive secretion of Growth hormone in adults.

• This produces a thickening and coarsening of bone.

• Individuals have:

  • A prominent forehead and jaw

  • Widened teeth

  • Abnormally large, spade-like hands (thich hands)

acromegaly xray

• An enlarged sella turcica (pituitary is in the sella turcica)

• Changes in the skull

benign tumors

localized tumor of well differentiated cells that don’t invade surrounding tissues or metastasize

neoplastic

new abnormal tissue growth

skeletal benign neoplastic diseases

• Osteochondroma (Additive) – Radiography and MRI

• Osteoma (Additive) – Radiography and MRI

• Giant cell tumors (Subtractive) – Radiography and MRI

skeletal malignant neoplastic diseases

• Osteosarcoma (Additive) – Radiography and MRI

• Ewing Sarcoma (Both) – Radiography and MRI

• Chondrosarcoma (Subtractive) – Radiography and MRI

Osteochondroma (additive)

• Most common benign bone tumor.

• 3x more common in men than women.

• Arises from the metaphysis.

• Most commonly, involves the lower femur or upper tibia.

• can have extoses

extoses

• Excessive benign bone growth.

• May appear as singular or multiple lesions.

• Normally diagnosed in childhood or adolescence.

osteochondroma xray

osteoma (additive)

• Most commonly located in the skull.

• Composed of very dense, well-restricted, normal bone tissue.

• Usually projects into the orbits or paranasal sinuses.

• Slow growing and of little significance, unless they cause:

  • Obstruction

  • Impinge on the brain or eye

  • Interfere with the oral cavity

osteoma xray

Giant Cell Tumors (GCT) (subtractive)

• Also known as osteoclastomas.

• Characterized by the presence of numerous, multinucleated osteoclastic cells.

• it is subtractive because it degrades the bone

• Affect women more than men between the ages of 20 and 30.

• GCTs can be either benign or malignant.

• Affects the epiphyses of long bones, especially the lower femur, the upper tibia, and the lower radius.

giant cell tumor xray

soap bubble

Osteosarcoma (additive)

• Also referred to as osteogenic sarcoma.

• Most common primary malignancy of the skeleton.

• The cause is linked genetically to deletion of genetic material on chromosome 13.

• Most frequently found in the metaphysis of long bones.

• Approximately 50% affect the knee.

• 75% occur in patients younger than 20 years old.

• spicules (small new bone cells) lifts the periosteum from the bone 

• Highly aggressive with a poor prognosis.

osteosarcoma xray

sunburst or sunray

Ewing sarcoma (sub and add)

• Occur usually between the ages of 5 and 15 years.

• More common in boys than girls.

• Often involves the entire shaft of a long bone. Specifically comes from the medullary canal

• Effects the extremities and the pelvis.

ewing sarcoma xray

Chondrosarcoma (subtractive)

• Arises from cartilage.

• Common locations are the pelvis, shoulder, and ribs.

• Men are 3x more likely than women to develop.

• lesions have the ability to seed. the traveling of the cancerous cells

• can destroy the bone

chondrosarcoma xray

• Irregular or circular radiolucencies with areas of calcification.