Hard Tissue Final

Question 1

Metastatic Bone Tumors
Primary Malignant Bone Tumors
General information

Answer 1

m/c malignant tumors of skeleton
• 70% are metastatic in origin
• 30% are primary tumors
• most are mets from a primary extra-skeletal focus- majority are epithelial in origin.

Question 2

Metastatic Bone Tumors
Primary Malignant Bone Tumors
Most common primary sites of origin

Answer 2

breast
• lung	* 80% of bone mets
• prostate		 are from these sites
• kidney
• thyroid
• bowel

Question 3

Metastatic Bone Tumors
Primary Malignant Bone Tumors
Female Metastasis stats

Answer 3

• breast cancer —————-70% bony metastasis

* thyroid, kidney uterus —–30% bony metastasis

Question 4

Metastatic Bone Tumors
Primary Malignant Bone Tumors
male Metastasis stats

Answer 4

• prostate cancer ————-60% bony metastasis
• lung ————————–20 % bony metastasis
- other ————————-20%

Question 5

Metastatic bone tumors

Clinical features

Answer 5

• usually 40 or older
	• recent weight loss
	• anemic
	• fever in advanced stages
MAJOR--->• principle sign:
		• persistent nocturnal pain
		• pathologic fracture

Question 6

Metastatic bone tumors

Clinical features cont.

Answer 6

• increased serum calcium in osteolytic mets;
however in most cases this is WNL.

• increased alkaline phosphatase and PSA with cancer of the prostate when capsule has been broken and Batson venous plexus has been seeded.
• occurs by direct invasion or seeding.
• not unusual to detect an metastatic lesion 10 to 15 yrs after treatment for a primary lesion

Question 7

Pathologic Features of Primary Malignant Bone Tumors

Pathways of metastasis
4

Answer 7

• Direct extension— soft tissue tumor lying adjacent to bone
eg; ca of uterus ==> iliac bone

• Lymphatic extension
uncommon because of lack of lymphatic channels- bone

• Hematogenous dissemination
• veins m/c pathway
• thick walls of arteries usually resist
- tumor penetration

• Batson’s venous plexus
  
  • provides passageway for cancer cells to invade bone

Question 8

Lytic vs. Blastic

Lytic lesions

Answer 8

• tumor emboli into bone marrow
• present a long time
• 50-70% of bone density lost before seen on radiograph
• lytic lesions occurs as a result of pressure erosion from medullary tumor deposits and are unrelated to osteoclastic activity.

*The “L’s”
Lytic, lucent, ladies, loss of bone density

Question 9

Radiologic features - bone scans 6

Answer 9

• detect 3% to 5% alteration of bone metabolism (mets).
• Tc-99m phosphate or diphosphonate (Tc-99mn-DP) .
• areas of metastasis appear hot = increased uptake.
• up to 40% of pt’s with abnl bone scans have nl x-rays.
• bone scans may detect mets ~ 18 months before they- are seen on x-rays.
• sensitivity 50 to 80% greater than conventional x-rays.

Question 10

Xray vs Bone Scan differences in bone density sensitivity

Answer 10

A bone scan can detect alterations of as little as 3% to 5%, while on
x-ray ~ 30 – 50% loss of bone density is needed before it can be detected
on x-ray. Detection = “hot” areas.

Question 11

Most involved part of spine for metastasis

Answer 11

most frequently involved components of the spine are the vertebral bodies and pedicles

Question 12

metastasis stats

Answer 12

• 28% in the ribs and sternum.
• 39% in the vertebrae.
• 13% in the pelvis.
• 10% in the skull.
• ~ 10% in the long bones.
• mets distal to the knees and elbows are rare.

Question 13

CT: Computed Tomography

gen info

Answer 13

• more sensitive than x-rays/plain film studies.
• useful in detecting cortical bone involvement.
• useful in detecting associated soft-tissue masses.

Question 14

MRI: Magnetic Resonance Imaging

gen info

Answer 14

• superior to CT in detection of both bone lesions and adjacentsoft tissue masses.
• infiltration of tumor cells into the fatty marrow is seen as ypointense on T1 weighted images, these areas show yperintense on T2 weighted images.

Question 15

Fundamental Roentgen Signs 4

Answer 15

• alteration of bone density and architecture

• 75% are osteolytic which is seen as:
  
  • moth-eaten
  • permative
• 15% are osteoblastic seen as :
  
  • snowball pattern
• 10% of metastatic lesions are seen as :
  
  • bubbly, highly expansile assoc.. w/ renal or thyroid malignancies

Question 16

Fundamental Roentgen Signs 3

Answer 16

• vertebral body and pedicles common sites of metastasis

• ivory vertebra seen in:
  
  • Pagets—increased size / enlarged
  • Hodgkins Lymphoma — anterior scalloping of vertebral body

• periosteal response is RARE

Question 17

Primary vs Secondary Tumors

Answer 17

Primary 			Secondary
30%				70%
expands bone
periosteal response
solitary lesion		multiple lesions
soft tissue. Mass

Question 18

Benign tumors

Answer 18

radiolucent lesion

well-defined margins

rim of sclerosis

cortex intact or thickened

may cause bone expansion without cortical destruction

bone adjacent to lesion is normal

short zone of transition

no soft tissue mass

no periosteal reaction or pain

Question 19

Malignant Tumors

Answer 19

bone destruction- (loss of density)

irregular, ragged, ill-defined- margin

poorly circumscribed areas- of increased density

cortical erosion or destruction

long zone of transition

may have soft tissue mass adjacent- to bone destruction

periosteal reaction

- spiculation
- sunburst	
- laminating
- Codman’s triangle

pain irregular cloud of density

Question 20

Metastatic Bone Tumors
Osteoblastic metastatic carcinoma
clinical features

Answer 20

> 40 yr old males
• persistent nocturnal pain
• weight loss

Question 21

Osteoblastic metastatic carcinoma

Radiologic features

Answer 21

• increased bone density - radiopacity
• snowball/cotton ball appearance
• vertebral bodies & pedicles common site
• ivory vertebrae

Question 22

Osteoblastic metastatic carcinoma

Lab

Answer 22

• increased acid phosphatase with prostatic cancer

* possible increased alkaline phosphatase

Question 23

Osteoblastic metastatic carcinoma

Misc. information

Answer 23

• 15% of metastatic lesions

* usually occurs 10-15 years after surgery or tx of primary - neoplasm (e.g. prostate cancer)

Question 24

Osteolytic metastatic carcinoma

Clinical features

Answer 24

• 40 + y.o. females
• pain at night
• wt loss
.

Question 25

Osteolytic metastatic carcinoma | Radiological features 5

Answer 25

* moth-eaten / permeative pattern * long zone of transition * vertebral bodies and pedicles commonly effected * one-eyed pedicles / winking owl sign * blind vertebra = bilateral lysis of pedicles

Question 26

Osteolytic metastatic carcinoma | • Misc. info

Answer 26

• 75% of all metastatic carcinoma ``` • usually occurs 10-15 years after surgery or tx of primary neoplasm (eg. Breast cancer). ``` • increased serum calcium.

Question 27

Primary Malignant Bone Tumors | 4

Answer 27

* 1 - Multiple myeloma * 2 - Osteosarcoma * 3 - Chondrosarcoma * 4 - Ewing’s sarcoma

Question 28

Multiple Myeloma | general info

Answer 28

* a.k.a. Kahler’s disease * • ~ 75% of pt’s are between 50 and 70 yrs of age; mean age 60. * rarely seen before the age of 40; few cases have been reported below 30. * male:female 2:1 * m/c primary malignant bone tumor

Question 29

Multiple Myeloma | clinical features

Answer 29

* 50-70 yr old males. * pain relieved with bed rest. * pain aggravated by weight bearing. * attacks: * spine m/c * pelvis * ribs * scapula

Question 30

Multiple Myeloma | labs

Answer 30

* reversed A/G ratio (albumin/globulin) * 40% show Bence Jones proteinuria * hypercalcemia is present in ~ 30% (2nd to lytic destruction aused by the myelomatous tissue.)

Question 31

Multiple Myeloma | radiologic features

Answer 31

* gross osteoporosis (only early sign) * punched-out lesions = Hallmark of disease * vertebra plana (uniform collapse) * raindrop skull (lytic lesions) * pedicle sign (pedicles visible or preserved on a collapsed vertebra)

Question 32

Multiple Myeloma Summary Solitary plasmacytoma

Answer 32

* represents a localized form of plasma cell proliferation. * m/c bones affected are mandible, ilium, vertebrae, ribs,- proximal femur and scapula. * typical lesion has a geographic, soap bubbled, highly

Question 33

Multiple Myeloma Summary Treatment & Prognosis

Answer 33

* 90% die within 3 years. | * tx is radiotherapy with chemotherapy.

Question 34

Solitary Plasmacytoma 5 | gen info

Answer 34

* represents a localized form of plasma cell proliferation. * is less common than multiple myeloma. * ~ 50% of pt’s present before the age of 50. * plasmacytoma is a localized form of multiple myeloma. * is less aggressive than the diffuse form of multiple myeloma.

Question 35

Osteosarcoma - a.k.a.

Answer 35

osteogenic sarcoma

Question 36

Osteosarcoma | gen info 3

Answer 36

• 1º malignant tumor of bone (undifferentiated connective tissue). • derived from undifferentiated connective tissue - forms neoplastic osteoid. • 2nd most common primary malignant tumor.

Question 37

Osteosarcoma | • 5 clinical types

Answer 37

* central osteosarcoma * multicentric osteosarcoma • parosteal osteosarcoma - (juxtacortical osteosarcoma). * secondary osteosarcoma * extraosseous osteosarcoma

Question 38

Osteosarcoma | Clinical features

Answer 38

* ~75% 10 to 25 yr. old males * painful swelling of the involved limb * most common sites: * distal femur * proximal tibia * proximal humerus

Question 39

Osteosarcoma | lab

Answer 39

* increased alkaline phosphatase | * levels are highest with the sclerotic type

Question 40

Osteosarcoma | radiological features 6

Answer 40

* ivory or sclerotic medullary lesion in the metaphysis of a -long bone * “sunburst” / “sunray” periosteal response * codman’s Reactive Triangle – often * cortical disruption w/ soft. tissue mass formation * cumulus cloud formation is the peripheral edge of an eccentric lobulated mass that has roughened and had irregular margins * TX: amputation (treatment of choice ????)

Question 41

Chondrosarcoma | gen info

Answer 41

* malignant tumor of chondrogenic origin that remains cartilaginous throughout its evolution. * third most common primary malignant bone tumor.

Question 42

Chondrosarcoma Clinical features 3

Answer 42

* 40-60 year old males. * pain after development of soft tissue mass - (occurs late in the disease process) * m/c sites: * pelvis * proximal femur * humerus * ribs * scapula * sternum * craniofacial bones * proximal tibia

Question 43

Chondrosarcoma | Radiologic features 6

Answer 43

* round, oval radiolucencies with ill-defined margins. * metaphysis or diaphysis. * popcorn matrix calcification in lesion 2/3’s of time. * radiolucent lesion 1/3 of time. * laminated or spiculated periosteal response. * contours of bone enlarged or expanded.

Question 44

Chondrosarcoma | Misc. information

Answer 44

• m\c primary malignant bone tumor of scapula. • of chondrogenic origin and remains essentially cartilagenous through-out its evolution.

Question 45

Ewing’s sarcoma | gen info 5

Answer 45

* 4th m\c primary malignant bone tumor. * represents ~ 7% of all primary malignant bone tumors. * decreased incident among African Americans. * is comprised of tumor cells derived from the connective tissue framework of bone marrow. * highly malignant tumor.

Question 46

Ewing’s sarcoma | clinical features

Answer 46

* 10-25 year old males. * pain with swelling at lesion site. * only primary malignant bone tumor with symptoms that simulate infection.

Question 47

Ewing’s sarcoma | Most common sites

Answer 47

* most common sites * long bones of the lower extremity. * femur * tibia * fibula * innominate =most common flat bone.

Question 48

Ewing’s sarcoma | signs and symptoms

Answer 48

• localized pain and swelling at the site of the lesion. • pain is dull at first and then it becomes severe - and persistent a few months prior to dx. • a soft tissue mass is often palpable. * systemic sx’s * slight to moderate fever. * increased ESR. * 2nd anemia. • Ewing’s appears to be the only primary malignant bone tumor with sx’s simulating infection.

Question 49

Ewing’s sarcoma | radiological features

Answer 49

* permeative lesion in diaphysis with onion skin periosteal response. * cortical “saucerization” = characteristic sign. * Codman’s triangle is frequently present (not as often as in osteosarcoma.)

Question 50

Quasi-malignant bone tumors | Giant Cell Tumor

Answer 50

* a.k.a. osteoclastoma * is a quasi-malignant bone tumor. * quasi-malignant * ~ 80% are benign * ~ 20% are malignant

Question 51

Giant Cell Tumor | Clinical features

Answer 51

* 20 to 40 year olds. * males -> malignant tumors. * females -> benign tumors. * aching pain with restricted motion

Question 52

Giant Cell Tumor | m/c sites (in decreasing order)

Answer 52

* distal femur * proximal tibia * distal radius • carries a more serious prognosis since most of these lesions are malignant. * proximal humerus * sacrum is the m/c site in the spine (~ 8% of cases).• it a benign tumor of the sacrum.

Question 53

Giant Cell Tumor

Answer 53

• usually begins in the metaphyseal end of a long bone • usually extends to the end of a long bone where it abutts the joint surface leaving the lesion ubarticular.

Question 54

Giant Cell Tumor | signs/symptoms

Answer 54

* is intermittent pain which is aching in nature. * localized swelling and tenderness. * frequently there is restricted motion present at the involved joint.

Question 55

Giant Cell Tumor | Radiologic features

Answer 55

• metaphysis and extends to subarticular location after- epiphyseal plate has closed. * radiolucent, eccentric metaphyseal lesion. * soap bubble expansion.

Question 56

Primary Benign Bone Tumors Osteochondroma gen info

Answer 56

* m/c benign skeletal tumor ~50% of all benign tumors. * bony exostosis projecting from the external surface of a bone. * usually has hyaline-lined cartilaginous cap.

Question 57

Osteochondroma | clinical features

Answer 57

* most osteochondromas are seen in pt’s in their childhood or adolescent years. * ~ 75% are seen in pt’s < 20 yrs of age (males). * the lesions are often not detected until later in life when the pt is x-rayed for another reason. * 2:1 male preponderance.

Question 58

Osteochondroma | Radiologic features

Answer 58

* the knee, tibia and femur are the m/c sites. * metaphysis m/c site of origin. * pedunculated type has an osteocartilaginous cap domed cap on a long slender stalk.

Question 59

Osteochondroma 2 types type 1

Answer 59

• sessile-------->>>> * broad flt base without a stalk. * humerus and scapula.

Question 60

Osteochondroma 2 types type 2

Answer 60

* pedunculated * has a long stalk attaching it to the bone. * knee, hip, and ankle. * “coat-hanger exostosis” = pedunculated. Growing away- from the joint on the metaphysis. * lesions appear as a cauliflower mass. * cap of exostosis is cartiginous (hyaline) and is often - lobulated.

Question 61

HME or Hereditary Multiple Exostosis

Answer 61

* unknown etiology. * inherited metaphyseal overgrowth with multiple osteochondromas - discovered b/w 2-20 - females = males - most commomly affects metaphysis of: knee, ankle, shoulder, wrist (usually bilateral)

Question 62

Hemangioma clinical features 4

Answer 62

* most lesions are seen in pt’s over 40 yrs of age (females > males). * most lesions develop after puberty and then remain undetected until later in life when they may be detected incidentally. * incidence is higher in females. * most lesions are asx at any body site.

Question 63

Hemangioma clinical features 3more

Answer 63

• most symptomatic spinal lesions are the result of expansion leading to the development of spinal stenosis. pt’s may present with impending paraplegia. • 70% to 75% of lesions occur in the spine, the lower thoracic and upper lumbar spine and the frontal bone are affected the most.

Question 64

Hemangioma | radiological features 5

Answer 64

* classic spinal lesion is on with coarse vertical striations within the vertebral body which has been called corduroy cloth appearance or striated vertebra. * prison bar * usually solitary * NO cortical endplate thickening • skull lesions are round or oval radiolucency radiating - “sunburst” or “spoked wheel”.

Question 65

Hemangioma radiological features 2 more

Answer 65

• vertebral expansion may rarely occur in hemangiomas creating - an appearance similar to that of Paget’s disease of the- spine. Differentiation is made by the lack of cortical- endplate thickening in hemangioma - a finding which- is present in Paget’s disease. • most skull lesions are found in the frontal bone, creating a - round or oval radiolucency, a radiating sunburst or - spoked wheel appearance that extends from the - center of the lytic defect.

Question 66

Hemangioma | tx and prognosis

Answer 66

• most lesions are clinically silent and do not require tx. • sx spinal lesions are either fx’ed or are expanding bone - creating spinal stenosis. * surgical decompression may be needed under these circumstances. * XRT may be used occasionally in inoperable vertebral hemangiomas. * skull lesions are easily tx’ed by en bloc excision and have a favorable- prognosis.

Question 67

Osteoma | gen info

Answer 67

• benign bone tumors arising in membranous bones. • most are asx; therefore true incidence is unknown. • most lesions are clinically silent. • most lesions occur in the frontal and ethmoid sinuses. • most are not id’ed until adulthood. • they may interfere with the drainage of a sinus or may lead to chronic - retro-orbital pressure, h/a’s, • most never reach a size > 2 cm. • they can become very large, nearly filling a sinus (giant osteoma).

Question 68

Bone Island aka

Answer 68

enostoma

Question 69

Bone Island | gen info

Answer 69

* a discrete area of solitary sclerosis within the skeleton. * usually asymptomatic. * bone islands can be 1-4 cm in size. * are common in the ischium, ilium, sacrum, proximal femur, - humerus, vertebra, talus, scaphoid and ribs. * do not occur in the skull. * are homogeneously dense and well marginated.

Question 70

Bone Island | clinical features

Answer 70

* clinical features * may be found at any age, are more common in adults than in children. * usually appear unchanged in size over many years. may grow on occasion. * etiology is unknown. * pathologic features * bone island represents a focus of compact lamellar bone located within normal spongiosa. * histologic appearance is the same as that seen with- osteopoikilosis. * the former is usually solitary and the latter consists of- multiple areas of sclerosis.

Question 71

Bone Island | pathological features

Answer 71

• is a focus of compact lamellar bone which is located within - normal spongiosa.

Question 72

Bone Island | radiological features

Answer 72

* usually intramedullary ovoid, round, or oblong radiopaque densities * has sharp margins. * may have thorn-like radiating spicules of bone referred to

Question 73

Osteoid Osteoma | Clinical features

Answer 73

* 2:1 male:female * 10-25 year old age group. * severe pain that is worse at night is characteristic. pain dramatically relievedby aspirin. * muscle atrophy and limp in long standing lesions. * ~ 50% are found in the femur and tibia. * ~ 10% occur in the spine, neural arch.

Question 74

Osteoid Osteoma | pathologic features

Answer 74

• tumor has a nidus, usually 1 cm or less in size.

Question 75

Osteoid Osteoma | radiologic features

Answer 75

• characteristic appearance of a cortical lesion is a radiolucent- nidus surrounded by florid reactive sclerosis.

Question 76

Osteoid Osteoma | differential dx

Answer 76

* Brodie’s abscess mimic's osteoid osteoma. * differentiation cannot be made clinically as both present with similar hx’s. * central nidus which is usually > 1cm in Brodie’s abscess suggests a difference.

Question 77

Solitary Enchondroma | gen info

Answer 77

* solitary enchondroma is a common benign bone tumor arising in- residual islands of cartilage left in the metaphysis as the - physis grows away. * appears as a single lesion within the interior of the bone. * has a predilection for the bones of the hand and feet. * often found incidentally. * most lesions are asx. * incidence * m/c benign bone tumor of the hand. * ~10% of all bone tumors.

Question 78

Solitary Enchondroma | clinical features

Answer 78

* tumor arises during the growth period. * most are seen between the ages of 10-30 yrs old. * males = females.

Question 79

Solitary Enchondroma | radiologic features

Answer 79

* hands and feet * hand - expansile lytic lesion of the phalanx. * usually within the metaphysis & centrally placed. * central matrix calcification * geographic lesion * central * thinned cortex * expansion * 50% stippled calcification * pathologic fx

Question 80

Multiple Enchondromatosis aka

Answer 80

(Ollier’s disease)

Question 81

Multiple Enchondromatosis | general features

Answer 81

* presence of central chondromas or enchondromas in multiple sites is - referred to an multiple enchondromatosis. * originally described a French physician Ollier. * enchondromatosis is a cartilage dysplasia of bone representing an inborn anomaly of enchondral bone formation. * this anomalous bone formation leaves unossified cartilagenous remnants in the diaphyses and metaphyses.

Question 82

Multiple Enchondromatosis | clinical features

Answer 82

* pain is rarely associated with the multiple enchondromas unless there is associated trauma or fracture. * large lesions are associated with deformity and loss of limb function. * most frequently involve small bones of the hands and feet. * femur and tibia are frequently involved. * iliac crest is the most frequently involved flat bone.

Question 83

Multiple Enchondromatosis | radiologic features

Answer 83

* lesions are similar to solitary enchondromas. * round or oval radiolucency that creates a symmetric widening of the bone. * central matrix calcification is common. * lesions can be eccentrically located causing bony expansion. * metaphyseal lesions often have streak-like or vertical bands of- radiolucencies projecting towards the diaphysis of the bone.

Question 84

Fibrous Xanthoma of Bone -Nonossifying Fibroma (NOF) | description

Answer 84

* Fibrous xanthoma is a term that includes several lesions under one - two major names: nonossifying fibroma (NOF) and fibrous - cortical defect (FCD). * most believe these two lesions to be identical lesions occurring in- pt’s of different age groups. * only differentiating factor is the pt’s age. * FCD occurs in the 4 to 8 yr old group. * NOF occurs in the 8 to 20 yr old group.

Question 85

Fibrous Xanthoma of Bone -Nonossifying Fibroma | general

Answer 85

* NOF has a lot of synonyms: * nonosteogenic fibroma * metaphyseal fibrous defect *  solitary xanthoma * xanthogranuloma of bone * fibrous medullary defect * thought to represent faulty ossification, rather than a true neoplasm.

Question 86

Fibrous Xanthoma of Bone -Nonossifying Fibroma | incidence

Answer 86

* majority of lesions are asx/silent therefore the true incidence is uncertain. * about 30% to 40% of normal children have FCD. * NOF is less common than FCD.

Question 87

Fibrous Xanthoma of Bone -Nonossifying Fibroma | • clinical features

Answer 87

* affects pt’s from 8 to 20 years. * average age affected is 14. * male:female is 2:1.

Question 88

Fibrous Xanthoma of Bone -Nonossifying Fibroma | signs/symptoms

Answer 88

* most lesions are asx. * most are found on x-rays taken for other reasons. * lesions > 8 cm cause persistent pain and may weaken the bone. * pathologic fx’s can occur; especially in teens/young adults.

Question 89

Fibrous Xanthoma of Bone -Nonossifying Fibroma | location

Answer 89

* m/c affects bones of the lower extremity. * distal tibia most frequent site. * other sites: * proximal tibia * distal femur * fibula * proximal humerus

Question 90

Fibrous Xanthoma of Bone -Nonossifying Fibroma | pathological

Answer 90

• NOF and FCD are identical histologically

Question 91

Fibrous Xanthoma of Bone -Nonossifying Fibroma | radiologic features

Answer 91

* typical lesion in NOF is a solitary, radiolucent, eccentric, and - is generally ovoid shaped. * often thins and expands the cortex. * has scalloped margins. * often has a multilocular, bubbly appearance. * osteolytic area varies from 2 to 7 cm.

Question 92

Simple Bone Cyst | general

Answer 92

* simple bone cysts are sometimes called unicameral bone cysts,solitary bone cyst, or juvenile bone cyst. * is not a true neoplasm * is a fluid filled cyst that is lined with a thin layer of fibrous tissue.

Question 93

Simple Bone Cyst | clinical features

Answer 93

* m/c occurs in pt’s between the ages of 3 and 14 years (80%). * male:female = 2:1. * most lesions are asx until a pathologic fx occurs. * about 2/3’s will develop pathologic fx’s. * m/c in the proximal humerus and femur (75% ).

Question 94

Simple Bone Cyst | pathologic features

Answer 94

• a simple bone cyst is a fluid-filled cavity present within the metaphyseal portion of the growing long bone.

Question 95

Simple Bone Cyst | radiologic features

Answer 95

* classic appearance is a geographic or cystic radiolucency which is broad at the metaphyseal end and narrower at the diaphyseal end. * lesion is radiolucent, except for a thin septa, which creates a bubbly or loculated appearance. * the loculation is pseudo or incomplete, because no complete septation- is present.

Question 96

Aneurysmal Bone Cyst - ABC | general features

Answer 96

• nonneoplastic solitary lesion of bone consisting of a cystic cavity filled with blood. • it is not an aneurysm and it is not a true cyst. • it is composed of channels containing flowing blood. • it has a sponge like appearance. • true pathogenesis is unknown.

Question 97

Aneurysmal Bone Cyst - ABC | clinical features

Answer 97

* ~75% of cases are seen in pt’s between the ages of 5 and 20 yrs old. * ~60% of cases are seen in females.

Question 98

Aneurysmal Bone Cyst - ABC | signs/symptoms

Answer 98

• c/c is the cute onset of pain at the affected site with a rapid increase in severity over a short time. .....pathologic fx’s are common • more so with expanding and destructive lesions. • spinal lesions may produce neurological sx’s; even paraplegia. • lesion prefers the neural which results in spinal stenosis. • a hx of trauma is often obtained in these pt’s.

Question 99

Aneurysmal Bone Cyst - ABC | location

Answer 99

* ~80% of lesions are located in long tubular bones and the spine. * ~20% of lesions affect the flat bones and short tubular bones. * femur and tibia m/c long bones affected.

Question 100

Tumor like Processes | Misc Conditions 2

Answer 100

1) Pagets | 2) Fibrous dysplasia

Question 101

Paget’s disease | general

Answer 101

* Sir James Paget described the disorder in 1877. * a.k.a Osteitis deformans * Paget’s disease is a great imitator of bone diseases, along with fibrous dysplasia.

Question 102

Paget’s disease | clinical features

Answer 102

* 2:1 male:female. * rare before age 40; m/c after age 55. * 90% of pt’s are asx. * pain, if present is of low intensity. Pain may associated with bowing deformities or fx. * m/c bones affected are pelvis, vertebrae, clavicle, humerus, ribs, with - the fibula being affected the least in uncomplicated form of Paget’s. *  increasing hat size is common. * subarticular location is common. Usually extends into the diaphysis.

Question 103

Paget’s disease | complications

Answer 103

• deformity of the involved bones. These include: shepherd’s crook deformity of the proximal femur (coxa vara), saber shin deformity (anterior tibial bowing), protrusio acetabuli, leontiasis ossea, frontal and parietal bossing, and basilar invagination. * pathologic fx of the vertebral body and transverse banana like fx of long bones is common. * pseudofractures are seen as areas of demineralization within the bone, which is replaced by fibrous tissue. * spinal stenosis may occur as a result of bony expansion of a vertebra, leads to compressive neuropathy.

Question 104

Paget’s disease | lab findings

Answer 104

• because of osteoclastic activity there is enhanced bone collagen destruction which causes an increase in urinary hydroxyproline. • alkaline phosphatase increases; sometimes 20x normal. • hypercalcemia can occur.

Question 105

Paget’s disease | pathologic features

Answer 105

* replacement of normal bone by pagetic, vascular, and fibrotic bone has been called mosaic structure of Paget’s disease. * four stages of pagets: * Stage one: osteolytic, destructive, monophasic. * Stage two: combined, mixed, biphasic. * Stage three: sclerotic or ivory. * Stage four: malignant degeneration.

Question 106

Stage one Pagets

Answer 106

osteolytic, destructive, monophasic

Question 107

Stage two Pagets

Answer 107

combined, mixed, biphasic

Question 108

Stage three Pagets

Answer 108

sclerotic or ivory

Question 109

Stage four Pagets

Answer 109

malignant degeneration

Question 110

Paget's Disease | radiologic features

Answer 110

* bone scan lesions will be hot. * skull lesions demonstrate the lytic stage of osteoporosis circumscripta,more advanced lesions of the combined stage show a cottonwool appearance. * spine: vertebra a thickened and enlarged endplate, creating a squared-off, picture frame vertebra. This occurs during the biphasic stage. * homogeneous increase in radiopacity of the vertebral body creates the ivory vertebra appearance. * m/c causes for Ivory Vertebra include: osteoblastic carcinoma, Paget’s disease, and Hodgkin’s lymphoma.

Question 111

Paget’s disease | radiologic features contsd

Answer 111

* pelvis: cortical thickening and bone expansion seen in the pelvis as thickening of the iliopectineal line, obliterating Kohler’s teardrop, this has been called the brim or rim sign. * long bones: tibia is the 2nd m/c site of lytic Paget’s disease, with the - skull being the m/c. Begins in the subarticular end of the - proximal tibia with extension down the shaft in a characteristic - candle flame or V-shaped appearance, this is often called - a blade of grass appearance.