Bone Soft Tumors

7/24/2019 Bone Soft Tumors

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BONE TUMORS



Bone Tumors & Tumor-Like Lesions



Bone Tumors & Tumor-Like Lesions



• Osteoma

•Osteoid Osteoma and Osteoblastoma

• Osteosarcoma



Osteoma

• Bosselated, round-to-

oval sessile tumors

• Subperiosteal surface of

cortex

• On or inside skull and

facial bones

• Usually solitary• Middle age



Osteoid Osteoma and Osteoblastoma

Osteoid osteoma – <2cm, teens and 20s,

M>F 2:1

–

Appendicular skeleton,posterior elements ofspine

– Cortex>medullary cavity

– Symptoms• Nocturnal pain

• Relieved by aspirin

Osteoblastoma

– >2cm

– Spine

– Symptoms• Dull, achy

• Unresponsive tosalicylates



Osteoid Osteoma and Osteoblastoma



Osteosarcoma

• Most common primary

malignant tumor (20%)

• Mesenchymal tumor

• Bimodal age distribution

• M>F (1.6:1)

• Metaphyseal region of long

bones



Osteosarcoma

Genetic abnormality

• RB

•

P53• INK4a (p16)

Characteristics

• Metaphysis of long

bones• Primary

• Solitary

• Intramedullary• Poorly differentiated



Osteosarcoma

Gross

• Big, bulky tumors

• Gritty, gray-white

• Areas of hemorrhage &cystic degeneration



Osteosarcoma

Microscopic

• Large hyperchromatic

nuclei

• Bizarre tumor giant cells

• Mitosis

• Formation of bone

• Coarse, lace likearchitecture



Osteosarcoma

Clinical Course

• Painful

• Progressively enlarging

mass• Reactive periosteal

formation

• Hematogenous spread

• (+) metastases: lungs,

bones, brain



• Osteochondroma

• Chondroma

•

Chondroblastoma• Chondromyxoid Fibroma

• Chondrosarcoma



Osteochondroma

• Exostosis

• Benign

• Attached to skeleton by

a bony stalk

• Most common benignbone tumor

•

Solitary• Autosomal dominant:

EXT1, EXT2

• Late adolescencce, earlyadulthood

• M>F (3:1)

• Endochondral origin

• Metaphysis, near growth

plate of long tubularbones (knee)



Osteochondroma

• Sessile

• Mushroom shaped

• 1-20cm

• Cap: benign hyalinecartilage covered byperichondrium

• Cortex of stalk mergewith host bone

• Slow-growing mass

• Can be painful

• Incidental finding

• Stop growing at timeof growth plateclosure

• Can give rise tochondrosarcoma



Osteochondroma

• FIGURE 26-25 Osteochondroma. A, X-ray of an osteochondroma arising off the posteriorsurface of the tibia. B, Axial CT scan shows continuity of the cortex of the bone and the

center of the osteochondroma. The fibula is adjacent to the mass. C, Gross specimen of

sessile osteochondroma composed of a cap of hyaline cartilage undergoing enchondral

ossification. D, The cartilage cap has the histologic appearance of disorganized growth

plate-like cartilage.



Chondroma and Enchondroma

• Benign

• Hyaline cartilage

• Bones of endochondral

origin

• Medullary cavity:

enchondromas

•

Surface of bone:subperiosteal /

juxtacortical chondromas

• 20-40’s

• Solitary

• Metaphyseal lesion of

tubular bones (shorttubular bones of hands

and feet)

•

Ollier disease(enchondromatosis)

• Maffucci Syndrome



Chondroma

• <3cm

• Gray-blue, translucent

• Well-circumscribed

nodules



Chondroma

•

Asymptomatic• Cause pathologic fracture

• Numerous, large tumors

•

C or O ring sign



Chondroblastoma

• Rare, benign tumor• Teens, M>F 2:1

• Knee

•Epiphyses and apophyses

• Sheets of chondroblasts

• Well-defined cytoplasmic

borders

• Moderate pink cytoplasm

• Hyperlobulated nuclei

• Chicken-wire mineralization

Scattered through the lesion are non-neoplastic

osteoclast-type giant cells.

Occasionally the tumors undergo prominent

hemorrhagic cystic degeneration.



Chondromyxoid firboma

• Rarest• Teens, 20’s

• M>F

• Metaphysis of longtubular bones

• 3-8cm

•

Well-circumscribed• Solid

• Glistening tan-gray



Chondrosarcoma

• Neoplastic cartilage

• Central (intramedullary)

vs peripheral

(juxtacortical andsurface)

• Conventional (hyaline

and/or myxoid), clear

cell, dedifferentiated,mesenchymal variants

•

Second most commonmalignant matrix-

producing tumor

• >40’s

• M>F 2:1

• Malignant hyaline and

myxoid cartilage

• Nodules of gray-whitetranslucent glistening

tissue



Chondrosarcoma

• Predominantly myxoid

– Viscous, gelatinous

tumors – Spotty calcifications

present

– Central necrosis

cystic spaces

• Grading



Chondrosarcoma

• Central portions of

skeleton

• Rarely involves distal

extremities• Painful, enlarging mass

• Imaging: endosteal

scalloping

Prognostic

• As grade progresses,

chance of metastases

increases (lungs,skeleton)

• >10cm – aggressive

Treatment• Wide surgical incision

• Chemotherapy



Fibrous Cortical Defect and Non-Ossifying Fibroma

• FCD common (30-50%, >2y/o)

• Metaphysis of distal femur and proximal tibia

• Bilateral, multiple

• 0.5cm – 5 or 6cm (non-ossifying fibroma)



Fibrous Cortical Defect and Non-

Ossifying Fibroma

Morphology

• Elongated, sharply

demarcated

radiolucencies• Surrounded by thin rim

of sclerosis



Fibrous Cortical Defect and Non-

Ossifying Fibroma

• Gray-yellow brown cellular

lesions with fibroblast and

macrophage

• Storiform (pinwheel)pattern

• Histiocytes are

multinucleated giant cells

or clusters of foamy

macrophages



Fibrous Dysplasia

• Benign tumor

• Does not differentiate to

mature structures

•

Mutation in GNAS gene

Patterns:1. Invovlement of single

bone (monostotic)

2. Invovlement of multiplebones (polyostotic)

3. Polyostotic disease, with

café-au-lait skin

pigmentation and

endrocrine abnormalities



Monostotic fibrous dysplasia

• 70% of cases

• M=F, early adolescence

• Stops enlarging at time

of growth plate closure

•Femur, tibia, ribs,

jawbones, calvaria,

humerus

• Asymptomatic

• Cause pain, fracture,

discrepancy in limb

length

Polyostotic fibrous dysplasia

w/o endocrine dysfunction

• 27% of cases• Early age

• Craniofacial involvement

•Crippling deformities

• Recurrent fractures



Polyostotic Fibrous Dysplasia

assoc. w/ café-au-lait

pigmentation andendocrinopathies

• McCune-Albright syndrome

•

3% of cases• Precocious sexual

development (F>M)

• Pigmentation: neck, chest,

back, shoulder, pelvic region

Polyostotic Fibrous Dysplasia assoc



Polyostotic Fibrous Dysplasia assoc.

w/ café-au-lait pigmentation and

endocrinopathiesMorphology

• Well-circumscribed

• Intramedullary

• Tan-white and gritty• Curvilinear trabeculae of

woven bone

•

Moderately cellularfibroblastic proliferation

• Trabeculae mimic

Chinese letters



Fibrosarcoma variants

• Collagen-producing with

fibroblastic phenotype

• Middle-aged, elderly

• M=F

Morphology

• Gross

• Large, hemorrhagic

• Tan-white mass• Destroy bone and extend

to soft tissues

Microscopic

• Malignant fibroblast

• Herringbone storiform

pattern

• Malignant fibrous

histiocytoma



Ewing sarcoma and Primitive

Neuroectodermal tumor (PNET)

• primary malignant small round cell tumors of

bone and soft tissue

• Identical chromosome translocation, differing

only in their degree of neural differentiation

– neural differentiation – PNETs

– undifferentiated - Ewing sarcoma





• 2nd most common group of bone sarcomas in

children

• 10 to 15 years old (~ 80% are < 20 years)

• Translocation: EWS gene on chromosome 22

and most commonly involved ETS gene is

FLI1, as part of a (11;22) (q24;q12)

translocation

– abnormal cell proliferation and survival



Sheets of small round cells with small amounts of clearcytoplasm

arises from the medullary cavity, invading the cortex, periosteum, and soft tissue.

tumor is soft, tan-white, and frequently contains areas of hemorrhage and necrosis

composed of sheets of uniform small, round cells that are slightly larger than lymphocytes with scant clear cytoplasm

Homer-Wright rosettes (tumor cells arranged in a circle about a central fibrillary space) is indicative of neural differentiation





• Diaphysis of long tubular bones (femur andflat bones of the pelvis)

• Systemic findings: fever,↑ sedimentationrate, anemia, and leukocytosis,

• Plain radiograms - destructive lytic tumor

– periosteal reaction produces layers ofreactive bone deposited in an onion-skin

fashion• Treatment: chemotherapy and surgical

excision with or without irradiation



Giant-cell Tumor

• Mixture of mononuclear cells and

multinucleated osteoclast-type giant cells

(osteoclastoma)

• Uncommon benign-locally aggressive

neoplasm

• RANK/RANKL signaling pathway



Abundance of multinucleated giant cells with background mononuclear

stromal cells

large, red-brown tumors that frequently undergo cystic degeneration

composed of uniform oval mononuclear cells that constitute the proliferating component of the tumor

osteoclast-type giant cells having 100 or more nuclei that resemble those of the mononuclear cells

necrosis, hemorrhage, hemosiderin deposition, and reactive bone formation are common secondaryfeatures

Giant Cell Tumor



Giant Cell Tumor

• Adults - epiphyses and the metaphyses

• Adolescents -limited to the metaphysis

• Majority arise around the knee

• Most are solitary

• Erode into the subchondral bone plate and

destroy the overlying cortex



Giant Cell Tumor

Magnetic resonance image

of a giant-cell tumor that

replaces most of the femoralcondyle and extends to the

subchondral

bone plate



Aneurysmal Bone Cyst

• Benign tumor

• Multiloculated blood-filled cystic spaces

• 17p13 translocations that result in up-

regulation of USP6, a deubiquitinating

enzyme



multiple blood-filled cystic spaces separated by thin, tan-white septa

walls are composed of plump uniform fibroblasts (which may be mitotically active),

multinucleated osteoclast-like giant cells, and reactive woven bone

bone is lined by osteoblasts that follow the contours of the fibrous septa





• Generally occurs during the first 2 decades of

life

• Metaphyses of long bones and the posterior

elements of vertebral bodies

• Radiograph- eccentric, expansile lesion with

well-defined margins

• Most lesions are completely lytic and often

with thin shell of reactive bone




Soft-tissue component is delineated by a

thin rim of reactive subperiosteal boneCharacteristic fluid-fluid levels



Metastatic Disease

• most common form of skeletal malignancy

Pathways

(1) direct extension

(2) lymphatic or hematogenous dissemination

(3) intraspinal seeding (via the Batson plexus of

veins)



Metastatic Disease

• adults: > 75% from cancers of the prostate,

breast, kidney, and lung

• children: neuroblastoma, Wilms tumor,

osteosarcoma, Ewing sarcoma, and

rhabdomyosarcoma

• most involve the axial skeleton > proximal

femur > humerus



REACTIVE TUMOR-LIKE LESIONS OFJOINTS



Ganglion Cyst

• ganglion cyst is a small (1 to 1.5 cm) cyst that

is almost always located near a joint capsule

or tendon sheath

• firm, fluctuant, pea-sized translucent nodule

• Usually around wrist joints

• Fluid-filled but non communicating

• Myxoid degeneration and softening of

connective tissue



Ganglion Cyst



Synovial Cyst

• Herniation of synovium through a joint

capsule or massive enlargement of a bursa

may produce a synovial cyst

• Baker cyst (RA setting)

• Synovial lining may be hyperplastic and

contain inflammatory cells and fibrin but is

otherwise unremarkable



Synovial Cyst

Vill d l S iti d Gi t C ll



Villonodular Synovitis and Giant Cell

Tumor of Tendon Sheath

• Group of benign neoplasms that develop in

the synovial lining of joints, tendon sheaths,

and bursae

• Consistent chromosomal aberrations

(neoplastic nature)

• Presents as a monoarticular arthritis that

affects the knee in 80% of cases



PVNS GCT



SOFT TISSUE TUMORS



Sources

• Fat

• Fibrous tissue and Fibrohistiocytic

• Skeletal muscle

• Smooth muscle

• Vascular

•

Peripheral nerve• Uncertain: synovial sarcoma, alveolar soft part sarcoma,

epitheliod sarcoma



Soft tissue tumors

• Causes of most are unknown

• Documented associations with radiation orprevious tissue injury

• Genetic syndromes – neurofibromatosis type 1 (neurofibroma,

malignant schwannoma)

– Gardner syndrome (fibromatosis)

– Li-Fraumeni syndrome (soft tissue sarcoma)

– Osler-Weber-Rendu syndrome (telangiectasia)



Soft tissue tumors

• 40% occur in the lower extremities, especiallythe thigh

• Fifteen per cent arise in children(4th most

common malignancy)• Grading (I to III) is based on degree of

differentation, mitoses, pleomorphism,necrosis

• Clinical staging involves the extent and size ofthe tumor



Soft tissue tumors



Soft tissue tumors



FAT

•lipoma

• liposarcoma

Normal fatLipoma,

encapsulated Liposarcoma, oftenretroperitoneal



Lipoma

• More common in women

• Benign soft tissue tumor composed of

differentiated fat cells

• Subcutaneous, mostly occur on the upper half

of the body (trunk, neck)

• Can occur in deep tissues (intramuscular,

intermuscular)

• 5th to 6th decade of life



Liposarcoma

• One of the most common sarcomas of adulthood

• 40s to 60s

• Arise in the deep soft tissues of the proximal

extremities and retroperitoneum

• Can be Well differentiated

• Myxoid

• Round cell type

• Pleiomorphic type



Fibrous tissue

• Nodular fasciitis(pseudosarcomatous)

• Fibromatoses

(plantar, palmar, penile)• Fibrosarcoma



Nodular fascitiis

• infiltrative or pseudosarcomatous fasciitis

• most common of the reactive pseudosarcomas

• often occurs in adults on the volar aspect of the

forearm

• arise in the deep dermis, subcutis, or muscle

• several-week history of a solitary, rapidly

growing, and sometimes painful mass

• Sometimes associated with preceding trauma



Nodular Fascitiis

Nodular fasciitis is richly cellular and consists of plump, immature-appearing fibroblasts

arranged randomly (simulating cells growing in tissue culture) or in short intersecting fascicles,

The cells vary in size and shape (spindle to stellate) and have conspicuous nucleoli and

abundant mitotic figures



Myositis Ossificans

• presence of metaplastic bone

• usually develops in athletic adolescents and

young adults

• follows an episode of trauma >50% of cases

• Early phase: swelling and pain

• Later stage: well circumscribed, firm mass

• Final stage: painless, hard, well-demarcated mass

• Progress in as little time as 3 weeks



Myositis Ossificans

MYOSITOS OSSIFICANS can be thought of as being a METAPLASTIC process, often following inflammationi.e.:

Usual scenario:InflammationFibrosis

Myositis Ossificans:InflammationFibrosisOssification



Superficial Fibromatoses

• Palmar (Dupuytren contracture) – irregular or nodular thickening of the palmar fascia

– progressive flexion contracture develops

– fourth and fifth fingers of the hand

• Plantar

– Similar to plantar fibromatoses, except contracturesand bilaterality are uncommon

• Penile (Peyronie disease) – palpable induration or mass appears usually on the

dorsolateral aspect of the penis

Deep seated Fibromatoses



Deep seated Fibromatoses

(Desmoid tumors)

• Borderland behavior

• Large, infiltrative masses recur afterincomplete excision

Extra-abdominal ( shoulder, chest wall, back, andthigh)

Abdominal ( Abdominal musculoaponeurotic inwomen)

Intra-abdominal ( Intra-abdominal; associated withFAP)



Fibrosarcoma

• Rare, malignant, collagen-forming non

pleomorphic, fibroblastic cell tumor, mainly of

adulthood, occasionally congenital

• Unencapsulated, well circumscribed, softmasses

• recurring in more than 50% of the cases and

metastasizing in more than 25%



Fibrosarcoma

Note the malignant spindle cells arranged in

a herringbone pattern



Skeletal Muscle

RhabdomyosarcomaRhabdomyoma



Rhabdomyosarcoma

• most common soft tissue sarcoma of childhoodand adolescence

• <20 years old

•

most occur in the head and neck orgenitourinary tract

• With embryonic, alveolar, and pleomorphicvariants

• Involve t(2;13)(q35;14) translocations

• Rhabdomyoblast - diagnostic cell



Rhabdomyosarcoma

Alveolar rhabdomyosarcoma

with numerous spaces lined by

tumor cells

Rhabdomyosarcoma composed of malignant

small round cells. The rhabdomyoblasts are

large and round and have abundant

eosinophilic cytoplasm.



Smooth Muscle

Leiomyoma

Leiomyomasarcoma



Leiomyoma

• Benign

• Most often arising from the uterus, but also

from erector pili muscles found in the skin,

nipples, scrotum, and labia

• tendency to develop multiple lesions is

thought to be hereditary



Leiomyosarcoma

• 10% to 20% of soft tissue sarcomas

• Skin and deep soft tissues of the extremities

and retroperitoneum

• Painless firm masses

• malignant spindle cells that have cigar-shaped

nuclei arranged in interweaving fascicles



Synovial Sarcoma

• Cell of origin is still unclear

• 20s to 40s

• deep soft tissue extremities

• 60% to 70% involve the lower extremities

• chromosomal translocation t(x;18) producing

SYT-SSX1 or -SSX2 fusion genes

• Commonly metastasizes to the lung, skeleton

k l



Unknown- Synovial Sarcoma

-dual line of differentiation of the tumor cells (i.e., epithelial-like and spindle cells); The

epithelial cells are cuboidal to columnar and form glands or grow in solid cords or aggregates,

The spindle cells are arranged in densely cellular fascicles that surround the epithelial cells



END

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