soft tissues

Question 1

General principles

Answer 1

benign outnumber malignant at least 100:1

metastasis tend to be “blood born” to lungs, liver, bone

40% lower extremity; especially thigh

30% trunk and retroperitoneum

bone involved by direct extension or metastasis

Question 2

Etiology

Answer 2

most common cause is unkown

associations: radiation, trauma (post massectomy: angiosarcoma, HHV8 (kapsi’s sarcoma), chemical exposure, and thermal burns

Question 3

Genetic syndromes

Answer 3

neurofibromatosis types 1: malignant peripheral nerve sheath tumor

gardner syndrome: fibromatosis (desmoid)

li-fraumeni syndrome (mutant p53): osft tissue sarcoma and other malignancies

hereditary hemorrhagic telangiectasia (osler-weber-rendu disease): teleangiectasias over skin and mucosal surfaces

Question 4

Ewing sarcoma and primitive neuroectodermal tumor

Answer 4

t (11:22) (q24;q12) EWS FLI1 fusion

Question 5

liposarcoma myxoid and round cell type

Answer 5

t(12:16)(p13;q11) FUS-DDIT3 fusion

Question 6

Synovial sarcoma

Answer 6

t(x;18)(p11;q11) SS18-SSX fusion gene

Question 7

rhabdomyosarcoma alveolar type

Answer 7

t(2;13)(q35;q14) PAX3-FOX01 fusion

Question 8

extraskeletal myxoid chondrosarcoma

Answer 8

t(9;22)(q22;q12) EWS-CHN fusion

Question 9

Age: What is most common for each age group

Answer 9

15% arise in children

rhabdomyosarcoma in children

synovial sarcoma in young adults

undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma) and liposarcoma in mid to late adulthood.

Question 10

What affects Prognosis

Answer 10

Type (recapitulation of tissue type)

stage (location and size): superficial vs deep, size, metastasis, etc

grade: cell pleomorphism, necrosis, mitotic

Question 11

Cell type: Spindle cell

Answer 11

rod shaped, long axxis at least twice short axis

fibrous, schwann cell, firbohistocytic, smooth msulce

Question 12

Cell type: small round (blue) cell

Answer 12

round, little cytoplasm

rhabdomyosarcoma, PNET/EWINgs

Question 13

Cell type: epitheliod

Answer 13

polyhederal; more cytoplasm

epithelioid sarcoma

Question 14

Cell type: matrix producing

Answer 14

bone, cartilage

extrasekeletal osteosarcoma

Question 15

Cell type: biphasic

Answer 15

spindle and epithelial cells

biphasic synovial sarcoma

Question 16

architectural patterns: fascicles of spindle cells

Answer 16

smooth muscle

Question 17

architectural patterns: short fasciles of spindle cells radiating from center (storiform; pinwheel-like)

Answer 17

fibrohistiocytic

Question 18

architectural patterns: nuclei in columns (palisading)

Answer 18

schwann cell

Question 19

architectural patterns: herringbone

Answer 19

fibrosarcoma

Question 20

architectural patterns: biphasic: spindle and epithelioid

Answer 20

synovial sarcoma

Question 21

lipoma: description, location, and convention

Answer 21

most common adult soft tissue tumor: soft, mobile. Painless with one exception (angiolipoma)

most common location: subcutaneous trunk and proximal extremities

conventional: thinly encapsulated yellow tumor. Lobules of mature fat

Question 22

other lipoma variaants

Answer 22

fibrolipoma: fibrous areas
angiolipoma: small vessels

dpinle cell lipoma: spindle cell areas

intramusclular lipoma: lipoma within muscle

Question 23

liposarcoma age, location, and types (4)

Answer 23

adults 40-60

deep soft tissues: retroperitoneum (often very large). Proximal extremities

types: well differentiated (retroperitoneal), myxoid/round cell (extremities), pleomorphic-very aggressive course, dedifferentiated

Question 24

liposarcoma, well differentiated: overview, gross, histo, growth description, genetics

Answer 24

most common type of liposarcoma

gross appearance same as lipoma

micro can be very close to benign lipoma: atypical spindle cells. Lipoblast: cytopalsmic vacuoles scallop nucleus

tend to be indolent with local recurrence

MDM2 amplification (inhibits p53)

Question 25

liposarcoma, myxoid/round cell: genetic, location, histo

Answer 25

t(12;16) FUS-DDiT3 fusion protein intramuscular, most often the thigh round cell component is aggressive: rare lipoblast myxoid tends to be indolent: chicken wire pattern of thin capillaries, rare lipoblast

Question 26

Liposarcoma, others

Answer 26

pleomorphic liposarcoma: very aggressive dedifferentiated liposarcoma: sarcoma arising from a well differentiated liposarcoma

Question 27

Fibrous (myofibroblastic) tumors/proliferations Types

Answer 27

benign reactive proliferations: nodular fasciitis, myositis ossificans fibromatoses: deep fibromatosis (desmoid), superficial fibromatosis fibroma fibrosarcoma

Question 28

nodular fasciitis: location, growth description

Answer 28

most common on volvar forearm solitary rapidly growing 2-3 cm: may be painful. 10% history of trauma deep dermis, subcutis, or muscle reactive process, rarely recurs if excised spindle cell proliferation of fibroblasts

Question 29

Myositis/panniculitis ossificans: age, cause, location, differentatiation

Answer 29

atheltetic adolescents and young adults 50% trauma subcutaneous and muslce early painful, circumscribed and firm 3-6 cm fibroblastic but later develops bone ends as trabecular bone with marrow

Question 30

fibromatoses types

Answer 30

superficial fibromatosis: palmer fibromatosis, plantar fibromatosis, penile fibromatosis deep seated fibromatosis (desmoid tumor): extra abdominal, abdominal, intra abdominal

Question 31

superficial fibromatosis: histo, differentiation,

Answer 31

nodular or poorly defined fascicles of fibroblasts and abundant collagen course: may progress, regress or stabilize may recur after excision

Question 32

Palmer fibromatosis (dupuytren's contracture)

Answer 32

nodular thickening of palmer fascia; puckers skin and digit flexion contraction (mostly 4 and 5) 50% bilateral

Question 33

Plantar fibromatosis

Answer 33

bilateral infrequent irregular of nodular thickening of plantar fascia

Question 34

penile fibromatosis (peyronie's disease)

Answer 34

induration of mass on dorsolateral penis can cause abnormal curvature of penis can constrict urethra

Question 35

deep-seated fibromatosis (desmoid tumors)

Answer 35

large infiltrative: locally aggressive, but does not metastasize teens-30s mutation in APC or b-catenin recur if not completely excised: wide margin needed

Question 36

deep seated fibromatosis types

Answer 36

abdominal: anterior abdominal wall, women during or after preganncy or c section. intra abdominal desmoid: mesentry and pelvic walls, gardner syndrome extra abdominal gray white poorly demarcated fibroiblasts in fascicles infiltrate tissue

Question 37

fibrosarcoma

Answer 37

rare; most common in deep extremities infiltrative fish-flesh with hemorrhage and necrosis spindle cell with areas of herringbone pattern 50% recur, 25% metastasize

Question 38

skeletal muscle tumors: types

Answer 38

rhabdomyoma cardiac rhabdomyoma rhabdomyosarcoma: embryonal, alveolar, pleomorphic

Question 39

rhabdmyosarcoma: age, location on body

Answer 39

most common soft tissue sarcoma of childhood and adolescence; rare after age 20 head/neck (nasal cavity, orbit, middle ear) gu tract

Question 40

embryonal rhabdomyosarcoma: age and subtypes

Answer 40

60% of rhabdomyosarcomas chidlren < 10 years subtypes: sarcoma botryoides in walls of hollow viscera and mucosal lined structures

Question 41

embryonal rhabdomyosarcoma: histo

Answer 41

soft gray infiltrative mass mimic skeletal muscle embryogenesis: round and spindle cells sarcoma botryoides variant: cluster of grapes protrude into lumen. Cambium layer: submucosal hypercellular area, best prognosis amongst embryonal rhabdomyosarcoma

Question 42

rhabdmyosarcoma: rhabdomyoblast

Answer 42

eccentric eosinophilic cytoplasm with thick and thin filaments tadpole cells and strap cells EM: sarcomeres myogenic markers positive: MYOD1, myogenin, desmin small round blue cell may see cross striations in some cells

Question 43

alveolar rhabdmyosarcoma: age, location in body, histo, genetic, prognosis

Answer 43

early to mid adolescence deep muscles of extremities fibrous septa divide tumor into alveolar-like spaces centrally containg discohesive cells while peripheral cells stick to wall t(2;13) or t (1;13): PAX3 or PAX7 to FOXO1 poor prognosis vs embryonal

Question 44

pelomorphic rhabdmyosarcoma: location in body, histology, caveats

Answer 44

deep soft tissue of adults very pleomorphic with rhabdomyoblasts often mistaken for undifferentiated pelomorphic sarcoma: desmin positive, myod1 or myogenin positive

Question 45

rhabdmyosarcoma prognosis ranking

Answer 45

sarcoma botryoides: best embroyonal: second best alveolar and pleomorphic: poor 65% of children are cured adults do poorly

Question 46

Leiomyoma: description, location,

Answer 46

benign smooth muscle tumor most common in uterus skin: erector pili, niipples, scrotum, labia. Pilar leiomyoma often painful and multiple. Adolescent and early adults. bland smooth muscle cells in fascicles rare in deep tissues

Question 47

Leiomyosarcoma: gender, description histo, tests

Answer 47

10-20% of soft tissue sarcomas F>M skin, deep extremities and retroperitoneum white masses can be large malignant spindle cells smooth muscle actin and desmin negative for MyoD1 and myogenin

Question 48

synovial sarcoma: age, location in body and histo. genetics

Answer 48

originally believed to recaptiulate synovium but cell of origin is unknown: <10% intra articular 10% of soft tissue sarcomas age 20-40 deep and around large joints: 60-70% lower extremities, especially knee/thigh. often microcalcifications on xray t(x;18) SYT-SSX1 or SYT-SSX2 fusion prognosis: 25-60% 5 years

Question 49

synovial sarcoma:

Answer 49

biphasic (dual) differentiation: epithelial cells as glands, cords, or nests. SPindle cells: cellular in fascilces monophasic (spindle cell) variant: positive for cytokeratins (epithelial marker), epithelial membrane antigen (EMA)

Question 50

undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma): description, pattern, location, histo

Answer 50

group of aggressive neoplasms cell pleomorphism and storiform pattern (diagnosis of exclusion) proximal extremities and retroperitoneum large grey, hemorrhagic and or necrotic metastasis 30-50%

Question 51

immunohistochemistry: epithelial membrane antigen and cytokeratin

Answer 51

general epithelial marker

Question 52

immunohistochemistry: MyoD1 and myogenin

Answer 52

skeletal muscle

Question 53

immunohistochemistry: actin and desmin

Answer 53

skeletal or smooth muscle

Question 54

immunohistochemistry: vimentin

Answer 54

nonepithelial tumors

Question 55

immunohistochemistry: smooth muscle actin

Answer 55

smooth muscle

Question 56

immunohistochemistry: Epithelium

Answer 56

cytokeratin and EMA

Question 57

immunohistochemistry: skeletal muscle

Answer 57

myoD1, myogenin, desmin and actin

Question 58

immunohistochemistry: smooth muscle:

Answer 58

desmin and actin

Question 59

immunohistochemistry: nonepithelial tumors

Answer 59

vimentin

Question 60

painful skin lesions "blue angel"

Answer 60

blue rubber bleb nevus angiolipoma neuroma (traumatic) glomus tumor eccrine spiradenoma leiomyoma (cutaneous)