• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

105 Cards in this Set

  • Front
  • Back

SMA/MSA, focal CD34 in fibroblasts

Fibroblastic differentiation
S100 (fat, lipoblasts), CD34 (spindled areas)
Lipomatous differentiation
CD31, CD34, SMA (pericytes), HHV8 (KS)
Vascular differentiation
S100, CD34, NFP, GFAP, EMA
Nerve sheath differentiation
Desmin, MyoD1 (nuclear), myogenin, myoglobin
Skeletal muscle differentiation
SMA, MSA, desmin
Smooth muscle differentiation
PAS crystals, no consistent IHC
Alveolar soft part sarcoma
Keratin, CD34, EMA
Epitheliloid sarcoma
Keratin, CK7, CK19, CD99, Bcl-2, EMA
Synovial sarcoma
HMB45 > S100, melan A, MITF (microphtalmia transcription factor), CD57, c-kit
Clear cell sarcoma
Translocation(s) in Ewing sarcoma?
11 = FLI-1
22 = EWS

21 = ERG
22 = EWS
t(11;22)? (2)
Ewing sarcoma
11 = FLI-1
22 = EWS

Desmoplastic small round cell tumor
11 = WT1
22 = EWS
Ewing sarcoma
21 = ERG
22 = EWS
t(12;22)? (2)
Clear cell sarcoma
12 = ATF1
22 = EWS

Myxoid/round cell liposarcoma
12 = CHOP = DDIT3
22 = EWS

Note: ATF1 and CHOP both map to 12q13
Translocation in desmoplastic small round cell tumor?
11 = WT1
22 = EWS
Translocation in clear cell sarcoma?
12 = ATF1
22 = EWS
Myxoid/round cell liposarcoma
12 = CHOP = DDIT3
16 = FUS = TLS
Translocation(s) in myxoid/round cell liposarcoma?
12 = CHOP = DDIT3
16 = FUS = TLS

12 = CHOP = DDIT3
22 = EWS
Translocation in alveolar soft part sarcoma?
X = TFE3
17 = ASPL
Alveolar soft part sarcoma
X = TFE3
17 = ASPL
Translocation in synovial sarcoma?
X = SSX1, SSX2, or SSX4
18 = SYT
Synovial sarcoma
X = SSX1, SSX2, or SSX4
18 = SYT
Translocation(s) in rhabdomyosarcoma, alveolar type?
1 = PAX7
13 = FKHR

2 = PAX3
13 = FKHR
Rhabdomyosarcoma, Alveolar type
1 = PAX7
13 = FKHR
Rhabdomyosarcoma, Alveolar type
2 = PAX3
13 = FKHR
Translocation in dermatofibrosarcoma protuberans?
17 = COL1A1 (collagen type 1)
22 = PDGF-beta (platelet derived growth factor)
Dermatofibrosarcoma proturberans
17 = COL1A1 (collagen type 1)
22 = PDGF-beta (platelet derived growth factor)
Translocation in low grade fibromyxoid sarcoma?
7 = CREB
16 = FUS
low grade fibromyxoid sarcoma
7 = CREB
16 = FUS
This sarcoma typically presents as single or multiple nodular, sometimes ulcerated, lesions involving the fingers, hands, and forearms of young adults (especially males). Histologically, it is recognized by its characteristic nodular pattern of growth, central cystic degeneration, and epithelioid cells with eosinophilic cytoplasm.
Epithelioid sarcoma
Typically affecting the shoulder or axillary region of male infants, this lesion displays 3 components: adipose tissue, some of which has tiny cytoplasmic droplets (brown fat); haphazardly placed paucicellular fascicles of spindle cells with abundant collagen; primitive-appearing rounded to spindled cells set in pale amphophilic stroma. There is no necrosis or mitoses.
Fibrous hamartoma of infancy
This benign tumor of infancy occurs exclusively on the fingers and toes. It consists of a dermal infiltrate of uniform, plump, spindled cells in a collagenous stroma. The spindled cells have a fascicular growth pattern. Mitoses can be prominent. There are numerous small round eosinophilic cytoplasmic inclusions within the spindle cells which stain deep red on Masson trichrome.
Infantile digital fibrosis
Which sarcoma tends to metastasize to other soft tissue sites rather than to lungs?
Myxoid liposarcoma
What is the classical location of spindle cell lipoma?
Neck or shoulder
t(9;22)(q22-31; q11-12)?

Note: this is not BCR-ABL
Extraskeletal chondrosarcoma
9 = CHN
22 = EWS

Note: skeletal chondrosarcoma doesn't have this translocation
Translocation in extraskeletal chondrosarcoma?
9 = CHN
22 = EWS
Occurring most commonly in the upper back, this benign tumor is composed of three types of cells: mulberry cell (multivacuolated adipocyte with a centrally placed round nucleus); cells with granular (rather than vacuolated) cytoplasm, and mature adipocytes.
This painful skin nodule tends to present in the legs and feet of females. Histologically, the tumor is composed of smooth muscle bundles that appear to originate from medium sized vessels.
Vascular leiomyoma
What does ANGEL stand for?
Neuroma (traumatic)
Glomus tumor
Eccrine spiradenoma
Leiomyoma (vascular)

ANGEL is the acronym for painful skin nodules
In the setting of HIV, what virus is implicated in leiomyosarcoma?
What are the most common demographic and sites for clear cell sarcoma of soft parts?
Demographic: 2nd-4th decades

Sites: Foot and ankle
What's the most common demographic and location for desmoplastic small round cell tumor?
Demographic: Young men (average age =22)

Site: Abdominal
What is the proliferative cell in nodular fasciitis?
What is the typical demographic and location for nodular fasciitis?
Demographic: 2nd to 5th decades

Site: Forearm

Other sites include upper extremity (shoulder), head and neck, and thigh.
What is the most common site of nodular fasciitis in children and infants?
Head and neck
Is nodular fasciitis usually deep or superficial?
Superficial (subcutaneous)
After local excision, is nodular fasciitis prone to recur?
No, local excision is usually curative though recurrences occur extremely rarely.
Is nodular fasciitis encapsulated?
This lesion has a "tissue culture" appearance, numerous mitoses (but no atypical forms), extravasated RBC in the stroma, mononuclear inflammatory cells and sparce multinucleated giant cells. The proliferative cells are positive for SMA with rare desmin positive cells. CD68 highlight histiocytes.
Nodular fasciitis
This lesion which tends to occur between the 3rd and 5th decades involving the extremities, is slowly growing, presents as slightly raised and pigmented cutaneous lesion centered in the dermis with associated epidermal hyperplasia. Histologically, the lesion is arranged in a storiform pattern or in short fascicles and is composed of spindled to oval fibroblasts and round to oval histiocytoid cells. The lesion also contains multinucleated, osteoclast-like giant cells; xanthoma cells may be seen and may be prominent. The stroma can be myxoid or densely fibrotic with a sparse chronic inflammatory infiltrate as well as focal hemosiderin pigment.
Fibrous histiocytoma
Is extraskeletal myxoid chondrosarcoma usually deep or superficial?
Is extraskeletal myxoid chondrosarcoma usually well-circumscribed or infiltrative? Is there a capsule?
Extraskeletal myxoid chondrosarcoma is usually well-circumscribed surrounded by a fibrous pseudocapsule.
Histologically, this tumor which is most commonly located in skeletal muscle, is multinodular with abundant myxoid matrix; the tumor cells are arranged in cords and clusters, frequently oriented radially. The tumor cells are round to stellate with eosinophilic cytoplasm, round and hyperchromatic nuclei, and sparse mitotic activity.
Extraskeletal myxoid chondrosarcoma
What demographic is most commonly affected with dermatofibrosarcoma protuberans?
Middle-aged males, African American predominance
What are the clinical characteristics of dermatofibrosarcoma protuberans?
Most cases are slow and progressive with a plaque-like phase followed by a nodular phase where the overlying epidermis becomes thinned and ulcerated.
The cut surface of this tumor is gray-white and the tumor involves the dermis and subcutis, sometimes extending to the underlying muscle. There is entrapped dermal collagen and appendages. The overlying epithelium is thinned or ulcerated. The tumor is cellular and composed of uniform, mildly atypical fibroblasts arranged in a monotonous, tight and repetitive storiform pattern.
Dermatofibrosarcoma protuberans
What is a dermatofibrosarcoma protuberans with malanocytic differentiation (i.e. S100+, melan A+, HMB-45+) called?
Bednar tumor
What is the juvenile variant of dermatofibrosarcoma protuberans called?
Giant cell fibroblastoma
What is the IHC for dermatofibrosarcoma protuberans?
Factor 13A
Dermatofibrosarcoma protuberans
CD34: +
S-100: -
SMA: -
Desmin: -
Keratins: -
EMA: -
CD99: +
Factor 13A: -
c-kit: -
What is the age of peak incidence for well-differentiated liposarcoma?
6th to 7th decades
What location is most commonly affected by well-differentiated liposarcoma?
Most common: deep muscles of extremities.

Less common: retroperitoeneum and contiguous areas (inguinal canal and paratesticular region).
What are the proliferative cells in malignant fibrous histiocytoma?
fibroblastic and myofibroblastic cells
IHC of malignant fibrous histiocytoma?
Malignant Fibrous Histiocytoma:
Vimentin: +
SMA: +
CK: -
S100: -
CD45: -
CD68: +
What is the peak age-range for malignant fibrous histiocytoma?
6th to 7th decades.

Note: MFH is rare before age 40.
What is the most commonly affected site of malignant fibrous histiocytoma?
What is the most common sarcoma arising after radiation therapy?
Malignant fibrous histiocytoma
What are the 4 types of malignant fibrous histiocytoma? What are the 2 most common?
Most to least common:
1. pelomorphic-storiform type
2. myxoid variant (>50% myxoid)

Less common:
- Inflammaotry: when inflammatory component becomes prominent, including abundant neutrophils
- Giant cell variant: when the giant cells become a predominant element
Name the 4 most common sarcomas.
1. MFH
2. Liposarcoma
3. Rhabdomyoarcoma
4. Synovial sarcoma
What's the typical demographic affected by synovial sarcoma?
Young adults (median age 30-35), but can occur in children and older people.
What is the most common site of involvement with synovial sarcoma?
Synovial Sarcoma

Most common:
Extremities (60% lower, 20% upper), typically arises in the proximity of large joints

Less common:
- Trunk
- head and neck
Is synovial sarcoma typically fast or slow growing?
Synovial sarcoma presents as a slow growing swelling, sometimes present for years. Poorly differentiated cases may present directly with metastases though.
What are the 3 microscopic types of synovial sarcoma list from most to least common.
1. Monophasic (~66%)
2. Biphasic (20-30%)
3. Poorly differentiated (least common)
What are the 3 types of rhabdomyosarcoma?
- Embryonal: includes botryoid, spindle cell, and anaplastic variants
- Alveolar: only type with a translocation
- Pleomorphic
Cambium layer, "strap cells", and rhabdomyoblasts characterize what lesion?
Embryonal rhabdomyosarcoma, botryoid variant
What are the first and second most common malignant soft tissue tumor of children?
1. Rhabdomyosarcoma
2. Ewings/PNET
What is the most common variant of rahbdomyosarcoma?
Embryonal rhabdomyosarcoma
What are the most common sites for embyronal rhabdomyosarcoma? (3)
Genitogurinary, retroperitoneal, head and neck
What is the most common site for embryonal rhabdomyosarcoma, spindle cell variant?
What demographic is affected by alveolar rhabdomyosarcoma and what are the 2 most common site of involvement?
Demographic: Older children (than embryonal rhabdomyosarcoma)

Sites: extremities, head/neck
What demographic is most commonly affected with pleomorphic rhabdomyosarcoma? What are the most common sites?
Pleomorphic Rhabdomyosarcoma:
Demographic: Elderly

Sites: trunk, extremities
Which is the most common type of rhabdomyosarcoma?
Embryonal RMS (75% of cases)
Alveolar rhabdomyosarcoma tends to have what type of giant cells?
wreath-like giant cells
IHC for rhabdomyosarcoma:
Myo D1 (nuclear)
Desmin: +
Actin: +
Myoglobin: +
Myogenin: +
Myo D1 (nuclear): +
CK: +/-
NFP: +/-
NSE: +/-
Leu7: +/-
S100: +/-
CD99: +/-
CD10: +/-
CD19: +/-
CD20: +/-
This rare variant of schwannoma contains melanin pigment and can be associated with Carney complex.
Psammomatous melanotic schwannoma
What is the EM finding in clear cell sarcoma?
The histology of this tumor consists of uniform cells arranged in small clusters, nests, and fascicles surrounded by delicate fibrous septa. The tumor cells have clear to eosinophilic cytoplasm, and uniform round to oval nuclei with vesicular chromatin and large nucleoli.
Clear cell sarcoma
What is the demographic affected by granular cell tumor?
Middle-aged (4th-6th decade), predilection for African-Americans
What % of granular cell tumors are malignant?
What is the most common soft tissue site affected by granular cell tumor?
How do the granules in granular cell tumor stain with PAS-D?

What are the granules made of?
PAS-D: +

Granules: phagolysosomes
Typical age group affected by Ewing/PNET?

Which ethnic group is usually spared of Ewing/PNET?
Affected group:
Adolescents, young adults

Spared group:
African Americans
Typical soft tissue sites for Ewing/PNET are? (4)
1. Paravertebral area
2. Retroperitonum
3. Chest wall
4. Extremities
What is the demographic which alveolar soft part sarcoma affects?
Children and young adults
Is alveolar soft part sarcoma fast or slow growing?
Dermatofibrosarcoma protuberans is to t(17;22)


Giant cell fibroblastoma is to _______?
ring chromosomes 17 and 22
The most common type of angiosarcoma is???
Cutaneous angiosarcoma not associated with lymphedema
The typical demographic affected by angiosarcoma is???
Elderly with sun-damage
3 positive IHC for angiosarcoma?
CD31, CD34, Factor 8
IHC for epithelioid hemangioendothelioma:
Factor 8
Epithelioid Hemangioendothelioma:
CD31: + (diffuse)
CD34: +/-
Factor 8: +/-
CK7: +/- (focal)
CK8: +/- (focal)
CK18: +/- (focal)
CK19: -
Are soft tissue epithelioid hemangioendotheliomas usually painful or not?

Solitary or multiple?

Superficial or deep?


Both superficial and deep
IHC for desmoplastic small round cell tumor?
Desmoplastic small round cell tumor:
Desmin +
CK +
WT1 +
CD99 +
Inflammatory myofibroblastic tumor is associated with what mutation?
ALK-1 on chromosome 2.

Note: 60% of IMT are ALK+ by IHC.
This lesion can affect people of all ages but has a predilection for young children (average age 10) and may present with systemic symptoms. Abnormal lab values include anemia, elevated ESR, thrombocytosis, and hypergammaglobulinemia. Microscopically, the lesion is characterized by 3 possible patterns: myxoid spindle cell lesion w/ tissue-culture-like appearance; cellular with fascicular-storiform archiecture; or spindle cells in a dense fibrous stromal background. The spindle cells may express ALK-1 by IHC.
Inflammatory myofibroblastic tumor
Solitary fibrous tumor IHC? (3)
CD34, CD99, Bcl2
What is Doege-Potter syndrome?
Hypoglycemia associated with solitary fibrous tumor.

Insulin-like growth factor is implicated. This only occurs in 4% of SFT. This is usually associated with larger tumors with higher mitotic rates.