Sarcoma, Benign Bone Tumors, Osteomyelitis, & Septic Arthritis

What is a carcinoma?

cancer of epithelilal tissues

What is a sarcoma?

cancer of non-epithelilal tissue

What is the most common presentation of soft tissue sarcomas?

asymptomatic mass

When s/sxs do occur in soft tissue sarcomas, why do they?

s/sxs secondary to pressure, traction, or entrapment of muscle or nerve by the mass

What s/sxs do occur in soft tissue sarcomas?

pain or numbness

What is the treatment for stage I (low-grade) soft tissue sarcoma?

surgery (wide excision with negative margins)

What is the treatment for stage II (small high-grade) soft tissue sarcoma?

surgery plus radiation

What is the treatment for stage III (large high-grade) soft tissue sarcoma?

surgery plus chemo (ex. doxorubicin, ifosfamide)

What is the treatment for stage IV (mets) soft tissue sarcoma?

chemo, ± other treatment

What are the cartilaginous types of benign bone tumors?

• enchondroma

• osteochondroma

• chondroblastoma

What are the bone-forming benign bone tumors?

• osteoid osteoma

• osteoblastoma

What cartilaginous bone tumor can metastasize to the lung?

chondroblastoma

What bone-forming benign bone tumor can become malignant

osteoblastoma, but very rarely this happens

What is a sarcoma?

cancer arising from mesenchymal origin.

What are mesenchymal cells?

precursor cells that can differentiate into bone marrow, bone, cartilage, tendon, fat, and muscle.

How are sarcomas classified?

by pattern of differentiation toward soft tissue types.

What is an adipose sarcoma known as?

liposarcoma.

What is a smooth muscle sarcoma known as?

leiomyosarcoma.

What is a skeletal muscle sarcoma known as?

rhabdomyosarcoma.

What is a blood vessel sarcoma known as?

angiosarcoma.

What is a joint sarcoma known as?

synovial sarcoma.

What is a fibrous connective tissue sarcoma known as?

fibrosarcoma.

What is a bone sarcoma known as?

osteosarcoma.

What are the two broad categories of sarcomas?

derived from bone, derived from soft tissue.

How common are sarcomas?

Sarcomas are rare, accounting for less than 1% of all malignancies.

What is one of the most common solid tumors in childhood?

Sarcoma.

What is the ranking of sarcoma as a cause of cancer deaths in children?

5th most common cause of cancer deaths in children.

What is the incidence of soft tissue sarcomas?

3 cases per 100,000 population.

Where do soft tissue sarcomas most commonly occur?

• 60% extremities (lower extremities 3x more than upper)

• 30% trunk

• 10% head and neck.

What are etiologic factors for soft tissue sarcomas?

• chemicals

• radiation

• genetics

• HIV/HHV (Kaposi’s sarcoma)

• immunosuppressive medications.

Do benign soft tissue lesions commonly transform into malignancy?

benign soft tissue lesions rarely transform into malignancy.

What benign lesions can transform into malignant soft tissue tumors?

neurofibroma → neurofibrosarcoma or malignant schwannoma.

Where can sarcomas rarely arise from?

sites of prior injury or surgery.

What is the role of X-ray in diagnosing soft tissue sarcomas?

Evaluate bony abnormalities.

What is MRI best for in soft tissue sarcomas?

Best for tumors of extremities, head, and neck.

What is CT best for in soft tissue sarcomas?

Best modality for evaluating the chest.

What is the most common site of metastasis in soft tissue sarcomas?

Lungs.

What other imaging is CT useful for?

chest/abdominal and visceral/retroperitoneum imaging.

What confirms the diagnosis of soft tissue sarcoma?

Biopsy.

Which masses require biopsy?

All new and persistent or growing masses.

What system is used for staging soft tissue sarcoma?

TNM System (plus G).

What does the TNM(G) staging system include?

• T - size of primary tumor

• N - node status

• M - metastasis

• G - histologic grade.

What locations have differences in scoring systems?

• Extremity/Trunk

• Head/Neck

• Retroperitoneal

• Abdominal/Thoracic Viscera.

What is the prognosis if there are no metastases?

If no mets – cure is common.

What is the prognosis if metastases are present?

If mets – small % can be cured.

What is the median survival for Stage IV disease with treatment?

13–18 months.

What are the most important prognostic factors in soft tissue sarcoma?

• Histologic grade

• Size of primary tumor

• Pathologic stage.

What is T1 in soft tissue sarcoma (trunk & extremity)?

Primary tumor ≤ 5 cm in greatest dimension.

What is T2 in soft tissue sarcoma (trunk & extremity)?

> 5 cm and ≤ 10 cm in greatest dimension.

What is T3 in soft tissue sarcoma (trunk & extremity)?

> 10 cm and ≤ 15 cm in greatest dimension.

What is T4 in soft tissue sarcoma (trunk & extremity)?

> 15 cm in greatest dimension.

What is N0 in soft tissue sarcoma (trunk & extremity)?

No regional lymph node metastasis.

What is N1 in soft tissue sarcoma (trunk & extremity)?

Regional lymph node metastasis.

What is M0 in soft tissue sarcoma (trunk & extremity)?

No distant metastasis.

What is M1 in soft tissue sarcoma (trunk & extremity)?

Distant mets present.

What is Stage 1A soft tissue sarcoma (trunk & extremity)?

T1, N0, M0, G1 or GX.

What is Stage 1B soft tissue sarcoma (trunk & extremity)?

T2, T3, or T4, N0, M0, G1 or GX.

What is Stage II soft tissue sarcoma (trunk & extremity)?

T1, N0, M0, G2/3.

What is Stage IIIA soft tissue sarcoma (trunk & extremity)?

T2, N0, M0, G2/3.

What is Stage IIIB soft tissue sarcoma (trunk & extremity)?

T3, or T4, N0, M0, G2/3.

What is Stage IV soft tissue sarcoma (trunk & extremity)?

Any T, N1, M0, any G OR any T, any N, M1, any G.

What is an enchondroma?

Benign bone tumor composed of cartilage (13% on benign bone growths).

What malignant tumor can an enchondroma become?

chondrosarcoma, but <1% of the time.

Are most enchondromas symptomatic?

Most are asymptomatic.

What symptoms can enchondromas progress to?

pain, swelling, deformity.

When do enchondromas usually present?

second decade (can be any age).

How can enchondromas present in adulthood?

pathologic fracture.

What increases risk of pathologic fracture in enchondroma?

• wt-bearing bone

• lesion >25 mm

• >50% diameter of cortex.

What are X-ray findings of enchondroma?

Oval, well-circumscribed, lucent defect +/- punctate calcifications, cortical thinning +/- sclerosis.

Where are enchondromas usually located?

long bones of hands/feet (50%) or humerus/femur (metaphysis).

What is the treatment for enchondroma?

No Tx necessary unless pathologic fx or symptomatic.

How are asymptomatic enchondromas monitored?

monitor with serial x-rays.

What is treatment for symptomatic enchondroma?

curettage and bone graft.

What is an osteochondroma?

Benign tumor, composed of cartilage.

What % of benign bone tumors do osteochondromas make up?

20-50%.

What malignant tumor can osteochondroma become?

chondrosarcoma.

When does osteochondroma usually present?

second decade.

Which sex is more affected by osteochondroma?

Males > Females.

How does osteochondroma usually present?

painless mass.

What symptoms can osteochondroma cause?

• pain

• impingement

• limited ROM

• deformity, fracture.

What are X-ray findings of osteochondroma?

• outgrowth from edge of growth plate (metaphysis)

• Bony base covered with cartilage

• Cortical and medullary continuity.

Where are osteochondromas usually located?

around the knee (distal femur #1) or proximal humerus.

What is the treatment for osteochondroma?

Usually nonoperative management and monitoring.

When is surgical excision indicated for osteochondroma?

• symptomatic or concern for malignant change

• Cartilage > 2 cm

• increase in size after skeletal maturity, new symptoms

• More central lesions

• Irregularities, erosions.

What is a chondroblastoma?

benign, cartilage-forming tumor.

What % of bone tumors do chondroblastomas make up?

extremely rare, <1% of bone tumors.

Which sex is more affected by chondroblastoma?

Males > Females.

When does chondroblastoma usually present?

Teenage years.

What are symptoms of chondroblastoma?

low-grade, constant joint pain, swelling.

What additional findings may occur in chondroblastoma?

joint effusion, limited ROM, tenderness.

What are X-ray findings of chondroblastoma?

lucent, round/oval, well-defined, sclerotic rim, Fuzzy-appearing calcifications in ~50%.

Where does chondroblastoma most often occur?

epiphysis/apophysis of long bones.

Where does chondroblastoma rarely occur?

flat bones/hands/feet.

What is the treatment for chondroblastoma?

Surgical, with curettage +/- bone grafting.

Can chondroblastoma metastasize?

Can rarely metastasize to the lungs.

How is metastatic chondroblastoma treated?

resection.

What is the rarity of bone sarcomas?

more rare than soft tissue sarcoma (0.2% of all malignancies)

What are the most common types of bone sarcomas?

• osteosarcoma (osteogenic sarcoma)

• chondrosarcoma

• ewing’s sarcoma

What is an osteoid osteoma?

Benign, bone-forming tumor.

Where does osteoid osteoma most commonly occur?

Lower extremity most common (proximal Femur #1).