Soft tissue translocation

Question 1

Alveolar rhabdomyosarcoma

Answer 1

t(2;13)(q35;q14) with PAX3-FOXO1 fusion Most common (60% of cases)

t(1;13)(p36;q14) with PAX7-FOXO1 fusion

Question 2

Alveolar soft part sarcoma

Answer 2

der(17)t(X;17)(p11;q25) with ASPSCR1-TFE3 fusion

Same gene fusion present in subset of distinctive pediatric renal cell carcinoma

Question 3

Synovial sarcoma

Answer 3

t(X;18)(p11;q11)

involving SS18 (SYT) gene Fusions and SSX1 (most common), SSX2, or SSX4 (rare) and

Question 4

Aneurysmal bone cyst of soft tissue

Answer 4

17p13 rearrangements Involves USP6 gene

Question 5

Nodular fasciitis

Answer 5

t(17;22)(p13;q13) with MYH9-USP6 fusion

Question 6

Angiofibroma of soft tissue

Answer 6

t(5;8)(p15;q13) with AHRR-NCOA2 fusion

Question 7

Angiosarcoma

Answer 7

Amplification of 8q24 (MYC)

Characteristic of tumors arising in association with radiation or lymphedema

Question 8

Lipoblastoma

Answer 8

8q11-13 rearrangements Involves PLAG1

PLAG1 is also seen in PA

Question 9

Atypical lipomatous tumor

Answer 9

Ring form of chromosome 12;

amplification of MDM2, CDK4, CPM

Same tumor as well-differentiated liposarcoma

Question 10

Well-differentiated liposarcoma

Answer 10

Ring form of chromosome 12;

amplification of MDM2, CDK4, CPM

Same tumor as atypical lipomatous tumor

Question 11

Dedifferentiated liposarcoma

Answer 11

Ring form of chromosome 12,

amplification of MDM2, CDK4, CPM by FISH analysis

Also present in atypical lipomatous tumor/well-differentiated liposarcoma

Question 12

Deep “aggressive” angiomyxoma

Answer 12

Rearrangements of 12q14.3 Involves HMGA2

Also seen in pleomorphic adenomas

Question 13

Soft tissue chondroma

Answer 13

12q13-15 rearrangements Involves HMGA2

Also seen in PA and deep aggressive angiomyxoma

Question 14

Dermatofibrosarcoma protuberans

Answer 14

t(17;22)(q21;q13) with COL1A1-PDGFB fusion

Also present in giant cell fibroblastoma

Ring form of chromosomes 17 and 22 Not seen in giant cell fibroblastoma

Question 15

Giant cell fibroblastoma

Answer 15

t(17;22)(q21;q13) with COL1A1-PDGFB fusion

Also present in dermatofibrosarcoma protuberans

Question 16

Angiomatoid fibrous histiocytoma

Answer 16

t (2;22)(q33;q12) with EWSR1-CREB1 fusion

Most common (90% of cases); also present in clear cell sarcoma and malignant gastrointestinal neuroectodermal tumor

t(12;22)(q13;q12) with EWSR1-ATF1 fusion

Also present in clear cell sarcoma and malignant gastrointestinal neuroectodermal tumor

t(12;16)(q13;p11) with FUS-ATF1 fusion

Question 17

Extraskeletal myxoid chondrosarcoma

Answer 17

t(9;22)(q22;q12) with EWSR1-NR4A3 fusion Most common

Question 18

Clear cell sarcoma

Answer 18

t(12;22)(q13;q12) with EWSR1-ATF1 fusion Most common (90% of cases); also present in angiomatoid fibrous histiocytoma and malignant gastrointestinal neuroectodermal tumor

t(2;22)(q33;q12) with EWSR1-CREB1 fusion Also present in angiomatoid fibrous histiocytoma and malignant gastrointestinal neuroectodermal tumor

Question 19

Malignant gastrointestinal neuroectodermal tumor

Answer 19

t(2;22)(q33;q12) with EWSR1-CREB1 fusion Also seen in clear cell sarcoma and angiomatoid fibrous histiocytoma

t(12;22)(q13;q12) with EWSR1-ATF1 fusion Also present in clear cell sarcoma and angiomatoid fibrous histiocytoma

Question 20

Desmoplastic small round cell tumor

Answer 20

t(11;22)(p13;q12) with EWSR1-WT1 fusion

Question 21

Ewing sarcoma

Answer 21

t(11;22)(q24;q12) with EWSR1-FLI1 fusion Most common (85% of cases)

t(21;22)(q22;q12) with EWSR1-ERG fusion

t(2;22)(q33;q12) with EWSR1-FEV fusion

t(7;22)(p22;q12) with EWSR1-ETV1 fusion

t(17;22)(q21;q12) with EWSR1-ETV4 fusion

Very rare fusions involving FUS

Question 22

Extrarenal rhabdoid tumor

Answer 22

Deletion of 22q11.2 Inactivation of SMARCB1 (a.k.a. INI1 or SNF5)

Question 23

Desmoid-type fibromatosis

Answer 23

CTNNB1 (β-catenin gene) mutations in sporadic lesions

APC mutations in tumors arising within setting of Gardner syndrome

Question 24

Epithelioid hemangioendothelioma

Answer 24

t(1;3)(p36.3;q23-25) with WWTR1-CAMTA1 fusion

Nearly all cases

Question 25

Infantile fibrosarcoma

Answer 25

t(12;15)(p13;q26) with ETV6-NTRK3 fusion Identical aberration seen in cellular mesoblastic nephroma of the kidney and MASC

Question 26

Hemosiderotic fibrolipomatous tumor

Answer 26

t(1;10)(p22;q24) with TGFBR3-MGEA5 fusion Also present in myxoinflammatory fibroblastic sarcoma

Question 27

Epithelioid fibrous histiocytoma

Answer 27

2p23 (ALK gene) rearrangements Most cases

Question 28

Gastrointestinal stromal tumor

Answer 28

KIT, PDGFRA mutations Rare: Mutations in SDH subunit genes (usually SDHB) or NF1

Question 29

Inflammatory myofibroblastic tumor

Answer 29

2p23 rearrangements Results in ALK gene fusion

Question 30

Epithelioid sarcoma

Answer 30

22q11-12 abnormalities Inactivation of SMARCB1 (a.k.a. INI1 or SNF5)

Question 31

Intramuscular myxoma

Answer 31

GNAS gene mutations

Question 32

Myxoid liposarcoma

Answer 32

t(12;16)(q13;p11) with FUS-DDIT3

Question 33

PEComa

Answer 33

Deletion of 16p Loss of TSC2

Question 34

Low-grade fibromyxoid sarcoma

Answer 34

t(7;16)(q33;p11) with FUS-CREB3L2 Most common (65-70% of cases); also present in some cases of sclerosing epithelioid fibrosarcoma t(11;16)(p11;p11) with FUS-CREB3L1 Rare

Question 35

Myxoinflammatory fibroblastic sarcoma

Answer 35

t(1;10)(p22;q24) with TGFBR3-MGEA5 fusion Also present in hemosiderotic fibrolipomatous tumor

Question 36

Ossifying fibromyxoid tumor

Answer 36

6p21 rearrangements Involves PHF1

Question 37

Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma

Answer 37

t(7;19)(q22;q13) with SERPINE1-FOSB fusion

Question 38

Solitary fibrous tumor

Answer 38

12q13 aberrations Intrachromosomal rearrangement results in characteristic NAB2-STAT6 fusion

Question 39

Mammary-type myofibroblastoma

Answer 39

Loss of 13q14 (RB1) Same as spindle cell/pleomorphic lipoma and cellular angiofibroma

Question 40

Spindle cell/pleomorphic lipoma

Answer 40

Loss of 13q14 (RB1) Also present in mammary-type myofibroblastoma and cellular angiofibroma

Question 41

Cellular angiofibroma

Answer 41

Loss of 13q14 (RB1) Same abnormality in mammary-type myofibroblastoma and spindle cell/pleomorphic lipoma

Question 42

Spindle cell liposarcoma

Answer 42

Loss of 13q14 (RB1)

Question 43

Chondrosarcoma

Answer 43

IDH1 and IDH2 mutations