Bone And Soft Tissue

Front 1

young patient with tumor in the metaphysis of the distal femur

Rads: cortex and medullary cavity along line of normal bone, along tendon

Gross: <2cm lesion OUTSIDE bone, thin blue-gray cap, underlying cancellous bone

Micro: cap: cartillage simulating normal epiphesal plate, chondrocytes in clusters, stalk of tumor is cancellous bone surrounded by fat and bone marrow

1. What is Nora's lesion?

Back 1

Osteochondroma

10% of bone tumors, 33% B9

1. bizzare paraosteal osteochondromatous proliferations in the digits

Front 2

younger patient with small bones in hands/feet with solitary tumor, can be multiple

Rads: rarification, thin cortex in small bones, no change in large bones

Gross: curretted fragments of gray/white tissue

Micro:hypocellular, bland cytology in long bones, myxoid change and moderately cellular in small bomes, NO invasion of medullary or cortical bone (abuts it)

1. what disease= multiple of these tumors?

Back 2

Enchondroma

1. Ollier's or Maffuchi's (with hemangiomas)

Front 3

20 YO with distal femur mass in the epiphesis

Rads: sclerotic rim, looks B9

Gross:

Micro: Mononuclear cells- oval/round nuclei, eosinophilic cytoplasm. nuclear grooves. Pink cartillagenous matrix, "chicken wire" calcification. Giant cells may be present

Back 3

Chondroblastoma

Front 4

middle aged man with mass in the pelvic bones/proximal femur or shoulder girdle

Rads: large, poorly marginated/miineralized mass with cortical abnormalities. Can be soft tissue

Gross: lobulated, pale blue/white, may be cystic, with myxoid and degenerative chage, permeates the cortex

Micro: hypercellular, large nuclei and hyperchromasia, invades cortex and medulary bone.

1. Grade?

2. treatment?

3. variants?

Back 4

Chondrosarcoma

1. 1,2,&3- cellularity and atypia

2. surgery- not responsive to chemo or rads

3. Dedifferentiated (in older patients, sarcomatous elements), clear cell (rare, lytic, clear cytoplasmic boundaries with clear cytoplasm, nucleolus), and mesechymal (younger patient with jaw tumor, hyaline cartilage juxtaposed with small round blue cell tumor)

Front 5

child/young adult with PAINFUL mass in the proximal femur, relieved by NSAIDs

Rads: small round nidus in the cortex

Gross: <1.5cm, well demarcated red/brown hemorrhagic appearance, sclerotic bone

Micro: irregular trabeculae of woven bone, surrouded by loose fibrovascular stroma, Giant cells, sharp demarcation from normal bone, oscteoclastic rimming.

Back 5

Osteoid osteoma

Front 6

young patient with mass in long bone or spine/jaw.

Rads: small round nidus in the cortex

Gross: >1.5cm, well demarcated red/brown hemorrhagic appearance, sclerotic bone

Micro: irregular trabeculae of woven bone, surrouded by loose fibrovascular stroma, Giant cells, sharp demarcation from normal bone, oscteoclastic rimming.

Back 6

Osteoblastoma

Front 7

young patient with distal femur or other long bone mass, in metaphysis

Rads: "codman's triangle", lytic, sclerotic lesion, destructive

Gross: fleshy yellow tan, heterogeneous. Does not go into epiphysis.

Micro: pervasive osteoblastic cells producing osteoid, grade 1-4.

1. Variants?

2. grading?

Back 7

osteosarcoma

2nd MC malignant bone tumor

Graded 1-4

1. Osteoblastic, chondroblastic, fibroblastic, telangictatic

2. grade1- <50% necrosis, 2- mostly necrotic, 3- 90-99%, 4- 100%

Front 8

young patient with knee mass

Rads: heavily mineralized mass attached to cortex by broad base

Micro: well formed trabeculae with spindle cells with minimal atypia; can have cartilagenous "cap", can dedifferentiate

2. What other similarly-named lesion is comprised of streamers of woven bone surrounded by bland spindle cells?

3. What other similarly-named lesion also arises from the cortical surface and shows malignant cartilage/myxoid change and malignant bone?

Back 8

paraosteal chondroma

2. Parosteal osteosarcoma

3. Periosteal osteosarcoma

Front 9

young patient with mass in the femoral neck or facial bones/ribs

Rads: well defined rarification, "ground glass" appearance

Gross: Fibrous appearing tumor, expanding bone, not destrictive

Micro: irregular angulated spicules of woven bone with bland spindle cells, occasional foam cells

Back 9

Fibrous dysplasia

1. assc. with albright syndrome

Front 10

child with long bone with cortex cavity

Rads: metaphyseal, eccentric, sclerotic rim

Micro: plump spindle cells, giant cells, mitoses, foam cells, inflammation

Back 10

Non-ossyfying fibroma (Metaphyseal fibrous defect)

Front 11

young male with tumor in pelvic girdle or lower extremities, MC in femur

Rads- infiltrative, destructive lesion with periosteal new bone formation "onion skin", in metaphysis and diaphysis

Micro: small round blue cells in sheets, have clear or eosinophilic cytoplasm. Can have rosettes

1. IHC?
2. Genetics?

Back 11

Ewings sarcoma

1. CD99 membranous, FLI1

2. t(11;22), FLI-EWS (also ERG-EWS)

Front 12

middle aged woman with solitary bone lesion in the distal femur/tibia, radius/sacrum/anterior spine

Rads: lytic bone lesion eccentric, cortical distruction (looks agressive)

Gross: red/brown mahogony, necrosis, curettings

Micro: numerous giant cells, round/oval mononuclear component with eosinophilic cytoplasm, reactive bone, mitoses, foam cells. Stromal/giant cell nuclei are similar

Back 12

Giant cell tumor

20% of B9 bone tumors

Local recurrence

Front 13

young patient with distal femur lesion, h/o other bone lesion in the area, may be in posterior spine

Rads: metaphysis lucency, cortical destruction, fluid levels

Gross: sold/cystic red brown mass

Micro: multiple cystic spaces separated by fibrous septa, c/o spindle cells s atypia, giant cells. calcs present

Back 13

Aneurysmal bone cyst

Front 14

young patient with humeral fracture

Rads: lytic lesion no wider than epiphyseal plate, may thin cortex

Micro: cyst wall fragments with bland spindle cells admixed with bone, irregular fibrinoid junk that may be calcified

Back 14

unicameral bone cyst

Front 15

middle aged man with mass arising from notochord elements (sacrum,base of skull,spine)

Rads: lytic lesion

Gross: lobulated re, glistening, translucent mass

Micro: chords/ nests of cells in a myxoid background, lobules separated by fibrous septa, eosinophilic cytoplasm with vacules.

IHC: CK, EMA, Bracyury +

Back 15

Chordoma

Front 16

M/C metastatic bone tumors?

1.
2.
3.

Back 16

1. Lung
2. Kidney
3. breast/prostate

Front 17

patient with a deep soft tissue mass.

Micro: spindled cell neoplasm with mono- or biphasic features with small cells in fascicles or whorls. Cells may be plump. Vessels are hemangiopericytoma-like.

IHC: CD99, BLC-2, EMA +

1. what is the classic translocation?

Back 17

Synovial sarcoma

1. t(x;18)

Front 18

Patient with h/o neurofibromatosis presents with a large mass attached to a peripheral nerve. May be painful.

Gross: fleshy white surface, necrosis and hemorrhage

Micro: sweeping fascicles of spindle cells with dense areas and myxoid areas. nuclei are wavy and have irregular contours.
ICH: S100, p53, myelin basic protein, CD57

Back 18

MPNST

Front 19

young man with rapildy-growing subcutaneous lesion on the upper forearm.

Gross: 2-5cm lesion that is well-circumscribed but has infiltrative borders

Micro: spindled cells (myofibroblasts) in a "tissue culture" arrangement, many mitoses but no atypia. Stroma contains extravesated RBCs, lymphocytes, rare giant cells. May have myxoid background.

IHC:SMA, HHF-35

Back 19

Nodular fasciitis

Front 20

young woman with soft tissue or abdominal mass, typically in a large muscle

Gross: whorled white firm surface and infiltrative margins

Micro: uniform spindle cells in long fascicles with a collagenous matrix, with long vessels separating fascicles. No atypia.

IHC: SMA+, desmin focal, S100/CD34-

Back 20

desmoid tumor (aggressive fibromatosis)

Front 21

younger AA man with chest or abdominal wall cutaneous mass (dermis) that is slow-growing. Skin may be ulcerated.

Micro: overlying dermis is thin, dermis contains cellular spindle cell lesion in storiform pattern that entraps dermal collagen. The cells have only mild atypia.

IHC: CD34+

Back 21

Dermatofibrosarcoma protuberans (DFSP)

Front 22

man with rapidly-growing thigh mass

Gross: gelatinous, hemorrhagic, necrotic mass

Micro: haphazard spindle cells evenly distributed in a myxoid matrix, with "chicken wire" small vessels in the background. May have a round cell component.

IHC: CD34-, S-100+ in round cell component

1. what is the common translocation?

2. What is in the myxoid matrix?

Back 22

myxoid liposarcoma

1. t(12;16)

2. hyalurdonic acid

Front 23

elderly person with rapidly growing mass in deep spoft tissue (MC in thigh). May have h/o radiation therapy

Gross: fleshy mass with hemorrhage and necrosis

Micro: infiltrative lesion c/o mixture of spindled and pleomorphic cells in a fibrous matrix. Occasional bizzare cells.

IHC: p63, CD68; CK, S-100, CD45-

1. what if there is a prominent inflammatory component?

Back 23

Malignant fibrous histiocytoma (MFH)

1. Inflammatory MFH

Front 24

Most common sarcomas in soft tissue:

1.
2.
3.
4.

Back 24

MC sarcomas

1. MFH
2. liposarcoma
3. rhabdomyosarcoma
4. Synovial sarcoma

Front 25

Young adult with a slowly enlarging swelling in the extremity near a joint

Gross: white mass abuts tendon near a joint

Micro: spindle cell lesion, 3 types- monophasic (MC), biphasic with glandular elements, and poorly differentiated.

IHC: CK, EMA, BCL2, CD99+; CD34-

1. MC translocation?

2. MC site of metastasis?

Back 25

Synovial sarcoma

1. t(X;18) SYT

2. lung (40%)

Front 26

1. Translocation in alveolar rhabdomyosarcoma?

2. in a clear cell sarcoma?

3. Alveolar soft parts sarcoma?

Back 26

1. t(2;13), FKHR gene to PAX3 or PAX7

2. t(12:22)

3: t(X;17) TFE3

Front 27

how can you differentiate a fibrous histocytoma from a DFSP?

2. How do you differentiate a hemangiopericytoma from a solitary fibrous tumor?

Back 27

fibrous histiocytoma is a dome-shaped mass in the extremities, DFSP is flat lesion that slowly becomes nodular in AA males. Very similar histologically...

2. they look the same histologically- if staghorn vessels seen- HPC. SFT is polymorphic and has cellular, myxoid, and collagenized areas.

Front 28

Age 15-25 years, no gender preference presents with dull, achy pain

Gross: 3-8 cm, well circumscribed, solid, glistening, yellow-white-tan, lobulated, zonation, "old" tumor more hyalinized; resembles hyaline cartilage; no myxoid change

Micro:
well circumscribed, hypocellular lobules of poorly formed hyaline cartilage composed of chondroblasts with abundant pink cytoplasm and myxoid tissue with fibrous septae containing spindle cells and osteoclasts; more cellular at periphery of nodules; tumor cells present in lacunae in myxoid areas, stellate in myxoid areas with long delicate cell processes that approach other cells; atypia is common, including large, hyperchromatic nuclei; scattered calcification and osteoclast-like giant cells, although fewer giant cells in old tumors; extensive vascularity is present in peripheral areas; no/rare mitotic activity

Back 28

chondromyxoid fibroma

Front 29

Any age, usually males, usually distal extremities

Gross: dermal or subcutaneous tumor

Micro: cavernous hemangioma and Kaposi sarcoma like features; cavernous spaces with solid areas composed predominantly of bland spindle cells, with a minor component of epithelioid, often vacuolated, endothelial cells, usually associated with irregular fascicles of smooth muscle fibers and adjacent malformed vessels

IHC: CD31, CD34

Back 29

Spindle cell hemangioendothelioma

Front 30

What is the distinction between a lipoma and a well-differentiated liposarcoma?

IHC?

Back 30

adipocytes have marked size variability, and at least focal nuclear atypia. Some scattered hyperchromatic stromal cells often seen.

S-100

Front 31

man with deep seated ans slow growing large mass, typically in the thigh or trunk

Gross: 3-8 cm mass that is (1) white and fleshy, with areas of necrosis or hemorrhage (2)well-demarcated, glistening, and resemble a uterine leiomyoma

Micro- monotonous uniform fibroblast-like spindle cells with little cytoplasm growing in long fascicles, classically in a 'herring bone' pattern. Mitoses seen, metaplastic bone or cartilege (2)- similar, but in a collagenous or myxoid background. Cells have pale eosinophilic cytoplasm with bland, tapered nuclei with nucleoli, no necrosis. Shows infliltration. Alternating collagenous and myxoid areas. May have tumor rosettes comprised of collagen

Back 31

1-fibrosarcoma

2- low grade fibromyxoid sarcoma

Front 32

older patient with mass in the deep dermis or subQ fat of limbs or limb girdles. May involve fascia and skeletal muscle.

Gross- gelatinous nodules along subQ fat that is partially necrotic/hemorrhagic

Micro- variant histology includes hypocellular myxoid areas and tumor cells with pleomorphic and hyperchromatic nuclei that aggregate around vessels. Vacuolated cells that resmble lipoblasts seen. Mitoses are rare.

2- Differentiate from epithelioid or pleomorphic liposarcoma?

Back 32

myxofibrosarcoma

2- S-100 negative, probably also t(12;16)

Front 33

young woman with dermal or subdermal mass, typically in the extremities.

Gross: indurated, well-deliniated plaque or nodule <1 cm

Micro: spindle cells in whorls/soriform pattern, intermixed with giant cells (touton), foamy macs, and interstitial fibrosis.thickened collagen bundles seen at the periphery of the lesion*. variants have variable cellularity, mitoses, vascular invasion, necrosis.

IHC: Factor XIIIa, CD68, KiM1p. NEGATIVE CD34

Back 33

fibrous histiocytoma (dermatofibroma)

Front 34

child with a head/neck mass, tyipcally in the eye/orbit, oropharynx, or parotid gland

Gross: poorly circumscibed fleshy mass

Micro: variable histology dependent on sub-type, consists of spindled/stellate cells with amphophilic cytoplasm that mature to cells with intensely eosinophilic cytoplasm that may be fibrillar,
Some well-differentiated cells have striations in the cytoplasm and the nucleus is pushed off to the side. Mitoses are frequent.

IHC: desmin, myogenin D, MyoD1

2- variant with linear arrangement of tightly-packed undifferentiated spindled cells with little cytoplasm lying in a parallel band beneath the epithelium

Back 34

Embryonal rhabdomyosarcoma

2- Botroid variant

Front 35

child or young adult with rapidly growing painless mass in the extremities.

Gross: fleshy mass 2-8 cm that is hemorrhagic or fibrous

Micro: round cells with variable differentiation into skeletal muscle. Characterized by fibrovascular setpa that separates the tumor into nests. Cells are discohesive in the middle of the nests. Multinucleated giant tumor cells (wreath cells) can be seen

2- mutation?

Back 35

Alveolar rhabdomyosarcoma

2- t(1 or 2;13) PAX3/PAX7 FKHR translocations. PAX 3 is more aggressive

Front 36

middle aged person with a soft tissue mass in (1) the abdomen or retroperitoneum or (2) visceral surface of the thorax or abdomen

Gross: well-circumscribed, solitary, lobulated mass

Micro: Bland spindled/ovoid cells around branched, hyalinized vessels (staghorn). (2) has these features plus broad areas of collagenization with "cracking" artifact. No pattern to spindled cell proliferation.

IHC: CD34, CD99+

Back 36

hemangiopericytoma/ SFT

Front 37

young man with a superficial dermal or deep soft tissue mass

Gross: fusiform, rubbery masses

Micro: cellular central regions and myxoid/paucicellular areas at the periphery. c/o spindled cells with wavy nuclei, along with scattered mast cells. Cells in "shredded carrot" pattern. Wagner-Messiner bodies.

IHC: s-100+, CD34/EMA +/-

Back 37

Neurofibroma

Front 38

Patient with an asymptomatic mass or hearing loss

Gorss: mass surrounding peripheral nerve that is yellow-tan and firm.

Micro: encapsulated* mass unless intracranial. Composed of areas that are cellular and others that are acellular. Cellular areas have Varocay bodies (nuclear palisading around cellular processes) and myxoid areas and hyalinized, thick walled vessels in acellular areas. Cytoplasm is deeply eosinophillic.

1- variant with only cellular areas, absent verucay bodies, and lymphocytes cuffing around the capsule.

Back 38

Schwannoma

Front 39

Proliferation of spindled cells in a loose stroma in deep soft tissue. Cells show minimal atypia and:

1. Have brightly eosinophilic cytoplasm in a dense myxoid/collagenous stroma. Cells show a t (11;22)

2. Cells are plump with occasional round cell forms. Areas with collagenous stroma and myxoid stroma. Stain positive for P63.

3. Areas of myxoid and collagenous/fibrous backgrounds. Curved vessels that can look plexiform t(6 of 7;16)

4. myxoid stroma with plexiform vessels. May see lipoblasts or round cells. t(12;16). S-100 +.

5. wavy nuclei, more cellular in the middle of the lesion. S100+.

6. vimentin, SMA, and weakly Desmin +

Back 39

1. Extraskeletal myxoid chondrosarcoma

2. Soft tissue myoepithelioma

3. Low grade fibromyxoid sarcoma

4. Myxoid liposarcoma

5. Neurofibroma

6. Fibromatosis