-Can malignantly degenerate into chondrosarcoma

1. Key clinical features.

   1. m/c primary benign tumor of the hand

   2. Can be Solitary or multiple (called Ollier’s Disease)

      1. Solitary enchondroma, is a benign tumor arising in the cartilage in the metaphysis as the physis goes away.

   3. Usually a painless incidental finding

   4. Most common complication is pathological fracture

2. Key radiological features.

   1. The bone looks less dense do to cartilage tissue within the bone

   2. 40% will uptake Ca++, giving a speckled appearance- a round lesion with polka dots

3. What is Ollier’s disease? (Multiple enchondromatosis)

   1. Enchondroma’s in multiple sites

1. Shares a common presenting complaint with what process?

   1. Brodie’s Abscess

      1. The radiolucent nidus of Brodie’s is much larger (>1 or 2cm)

      2. Hole will be in the marrow

      3. The halo rim of sclerosis surrounding the nidus is much thicker and more irregular

2. Key clinical features.

   1. Pain at night relieved by aspirin

   2. A “blister” on the bone between the cortex and the periosteum. Might show up as a hole or nidus, which is lucent.

3. Key radiologic features.

   1. The nidus or hole is usually surrounded by sclerosis.

-A cortical bone tumor with a smooth contour and a continuous cortex

-Are found:

Ocuping parts of the skull that SHB spaces (sinuses)

Attached to the skull as a raised lesion

1. What syndrome includes the Osteoma as part of its classic presentation?

   1. Gardener’s Syndrome

-Hemangioma, a primary benign neoplasm, is a slowly growing lesion of bone composed of newly formed capillary, cavernous or venous vessels.

1. Key clinical features

   1. M/c primary benign tumor of the spine

   2. No history of going malignant

2. Key radiologic features

   1. Corduroy cloth or striated vertebra appearance which is accentuated vertical trabeculae.

   2. Barrel shaped vertebra

   3. In the skull,, it appears as one large lesion. Most occur in the frontal bone, creating a round or oval radiolucency, radiating sunburst or poked-wheel appearance

-lesion consisting of a cystic cavity filled with blood.

1. Key clinical features?

   1. 75% 5-20 yoa

   2. Previous history of trauma. 80% occur in long bone (femur, tibia and spine)

2. Key radiological features

   1. Only benign bone tumor known to cross the epiphyseal plate

   2. Cortical ballooning or Blown-out appearance

   3. Periostel buttressing at the edge of the lesion is characteristic.

-Hereditary Multiple Exostosis is an inherited autosomal dominant metaphyseal overgrowth that is characterized by multiple osteochondromas

1. Key radiological features

   1. Multiple, painless lumps and bumps around joints

   2. Bayonet deformity of the wrist

   3. Broad metaphyses

   4. Calcified cauliflower cartilaginous caps

-Not to be confused with the congenital anomaly called Suprachondylar process.

-Also known as Coat-hanger exostosis

-Is a bony exostosis projecting from the external surface of a bone; usually has a cartilaginous cap.

1. Key clinical features

   1. Occurs ~20 yoa

   2. Points away from the joint, there is no ligament

   3. Most are asymptomatic. M/c complaint is a painless mass around the joint

2. Key radiological features

   1. 2 types of Osteochondroma:

      1. Sessile: On a broad, flat base and no stalk; common in the humerus and scapula.

      2. Pedunculated: On a long stalk, with a cauliflower top. Extending away from the joint.

   2. Coat-hanger exostosis represents the pedunculated.

   3. Has a continuous cortex until you reach the tip. Then it is cartilaginous

3. Most common complication

   1. Aggressive biopsy

   2. Trauma or fractures then can become malignant.

-Is a neoplasm that originates from non-bone forming supportive connective tissue of the marrow. Contains multiple nucleated giant cells

1. Clinical Features

   1. Males:

      1. Tumor tends to be malignant

   2. Females:

      1. Tumor tends to be benign

   3. 80% are benign, 60% are lytic

2. Key Radiologic features

   1. Most lesions begin in metaphysis and extend to subarticular location.

   2. Thin, expanded cortex, which gives the Soap Bubble Pattern in 40%

   3. May have delicate periosteal reaction.

   4. M/c in distal femor and proximal tibia

3. Most worrisome complication

   1. 20% of the time could be malignant

-primary malignant bone tumor that produces varying amounts of collagen and has no tendency to form tumor bone, osteoid, or cartilage, either in its primary site or in its metastases.

1. Age group?

   1. 30-50 years of age

2. Key clinical features.

   1. 2 types of lesions meduallary and periosteal

   2. pain and swelling for long duration

   3. the metaphysis is the classic location

   4. Most occur about the knee, femur, tibia, and humerus

3. Key radiological features

   1. Highly destructive meduallary lesion, lytic and placed within long bone

   2. Produces the largest soft-tissue mass of all primary malignant tumors

-Is a primitive primary malignant tumor of bone it is composed of tumor cells derived from the connective tissue framework of bone marrow

1. How common? Age group?

   1. 7% of all primary bone tumors. 4^th m/c primary malignant bone tumor behind (multiple myeloma, osteosarcoma, and chondrosarcoma).

   2. 10-25 years of age

2. Key clinical features

   1. Mimics: Infection; systemic signs of slight fever, secondary anemia leukocytosis, and increase ESR

   2. Affects long tubular bones of the Lower extremity.

3. Key radiologic features

   1. Saucerization: Cortical saucerization is a characteristic sign. This irregular defect effaces the outside of the bone occasionally, exhibiting a marginal scalloping effect.
      

   2. Classic presentation is a diaphyseal permeative lesion with a delicate onion skin or peel periosteal response.

   3. The most common primary malignant bone tumor to metastasize to bone

-Is a malignant tumor of chondrogenic origin that remains essentially cartilaginous throughout its evolution.

1. How common is Chondrosarcoma? What age group?

   1. Represents the third most common primary malignant bone tumor, following multiple myeloma and osteosarcoma.

   2. Age group is 40-60 years 2:1 male predominance.

2. Key clinical features

   1. Pain usually presents late in the disease process, often after large soft tissue masses develop

   2. Severe pain follows pathologic fracture

   3. The most common sites are the pelvis, proximal femur and humerus, ribs, scapula, sternum, craniofacial bones, distal femur, and proximal tibia. The normal variance notes states that Chonndrosarcoma is the m/c primary malignant tumor of the hand.

3. Key radiological features

   1. Round or oval radiolucencies with ill-defined margins evident.

   2. Lesions re metaphseal or diaphyseal

   3. Endosteal scalloping occurs secondary to pressure erosion from the enlarging lobular mass

   4. Popcorn matrix calcification in the lesion occurs in 2/3 of cases; 1/3 are purely radiolucent

   5. Laminated or speculated periosteal response occurs

   6. Metastatic disease is usually to lung

4. Prognosis

   1. Prognosis is good, with 90% survival after early surgery

-Is a primary malignant tumor of bone; it is derived from undifferentiated connective tissue and forms neoplastic osteoid

1. How common is Osteosarcoma? Age group?

   1. It is the second most common primary malignant bone tumor, representing 20% of all primary malignant bone tumors.

   2. It is 2x more common than chondrosarcoma, 3x more frequent than Ewings sarcoma.

   3. 75% of cases occur in the 10-25 year age range, with 2:1 male predominance.

2. Key clinical features.

   1. Painful swelling of the involved limb is a common presenting symptom

   2. The metaphyses of the distal femur, proximal tibia, and proximal humerus are the most common sites.

   3. Only 3.5-7% occur in the spine

3. Key radiologic features

   1. The classic lesion presents as a permeative or ivory medullary lesion in the metaphysis of a long tubular bone with a poorly defined zone of transition.

   2. A sunburst or sunray periosteal response is characteristic

      1. Sunburst= periosteal reaction that often takes place within an extracortical, dense soft tissue mass that displays transverse spicules or radiating striations.

   3. Often, Codman’s triangle is found associated with the destructive lesions

      1. This is a reactive response to the lifting of the periosteum and is not pathognomonic for osteosarcoma b/c it may also be found in benign conditions such as traumatic periostitis, osteomyelitis, eosinophilic granuloma, and thyroid acropachy.

   4. Cortical disruption with soft tissue mass formation, often growing to large dimensions, occurs. The peripheral edge of an eccentric lobulated mass whose margins are roughened and irregular may be referred to as the cumulus cloud appearance.

4. Prognosis

   1. A 20% 5-year survival rate has been traditional; studies using intensive chemotherapy report 80% survival rate

   2. Amputation has offered the best tx when the lesion is surgically accessible.

-is a disorder of unknown cause in which skeletal aberrations constitute the cardinal feature.

1. Key clinical features.

   1. Café au Lait spots with a “coast of Maine” appearance, pigmentation changes

   2. Common in late childhood before puberty during skeletal growth

   3. Polystotic m/c for derormities

2. Key Radiological features

   1. Clear zone in the center with a “Ground Galss Appearance” – beveled / fine fuzzy opaque edges

   2. Stimulates blastic reaction of surrounding tissue = “Rind of Sclerosis”

   3. Can change the contour of bone (expansile), with widening of meduallary, endostal thinning and scalloping

   4. Sheperds crook deformity common

1. Coast of Maine Café au Lait spots is associated with Polystatic fibrous dysphasia
   

2. Coast of California Café au Lait spots are associated with Neurofibromatosis

3. Most common malignancy of bone? METS
4. Most common primary malignancy of bone? Multiple Myeloma
5. Most common benign tumor of the hand? Enchondroma
6. Most common Primary malignancy of the hand? Chondrosarcoma
7. Most common benign tumor to a growth plate? ABC (Aneurysmal Bone Cyst)
8. Most common benign tumor of the spine? Hemangioma

Localized form of plasma cell proliferation

1. Key clinical features

   1. Most common bones affected: manible, ilium, vertebrae, ribs, proximal femur, and scapula.

2. Key radiographic features

   1. The typical lesion has a geographic, soap bubbled, highly expansile radiographic appearance.

3. Common Complications

   1. 70% of solitary plasmacytoma lesions develop into diffuse multiple myeloma

1. Multiple Myeloma

2. What does it look like on a bone scan?

   1. Bone scans are cold or normal except at sites of pathological fractures, which will be focally hot.

      1. This occurs because Multiple Myeloma causes the release of Osteoclast Activating Factor by the plasma cell. Bone scans depend on Osteoblastic activity. So when there is a fracture osteoblastic activity occurs.

3. Where is it primarily located

   1. Located primarily in the spine.

   2. Also located in the pelvis skull, ribs, and scapula.

4. Key clinical features.

   1. 75% of patients are between 50-70 yoa and 2:1 male preponderance

   2. LB Pain is the cardinal initial symptom relieved with bedrest and aggravated with weight. With sciatica

   3. Bacterial infections occur in 10% of cases most respiratory in nature.

   4. Pathological fracture is common complication

5. Key radiologic findings.

   1. Bone Scans are cold

   2. Gross osteoporosis may be the only early sign

   3. Punched lesions are the radiologic hallmark of myeloma

   4. Vertebra plana or wrinkled vertebra is characteristic.

   5. Raindrop skull (lytic myeloma defects) and pedicle sign of myeloma (preservation of pedicles) occur.

   6. “Moth Eaten,” Permeative lesions

   7. Foggy cortical – Medullary border

6. Key laboratory features.

   1. 40% show Bence Jones’ proteinuria.

   2. Immnoglobulin Electrophoresis – to Elevation of IgG

   3. May have infections do to decreased WBCs

   4. Normocytic, normochromic anemia

7. Prognosis

   1. 90% die within 3 years.

   2. Tx is usually radiotherapy, chemotherapy, and on occasion, local excision.

1. Direct Extension

   1. Direct invasion into a bone may occur from a soft tissue tumor lying adjacent to or near the bone.

   2. An example is carcinoma of the uterus which is known to cause direct extension to the iliac bones

2. Lymphatic Dissemination

   1. This is uncommon. It is thought that the absence of lymphatic channels in bone marrow is the reason for the relatively low incidence of lymphatic seeding of bone.

3. Hematogenous Dissemination

   1. Spread through blood vessels, particularly the veins, is the most common pathway for tumor emboli. The three most commonly seeded in this manner are the lungs, liver, and the axial skeleton.

   2. Batson’s Venous Plexus are valveless veins where blood can reflux when intrathoracic and intra-abdominal increases. Batson’s plexus also provides a series of venous passageways by which cancer cells can be directly seeded into bones.