Soft Tissue and bone Flashcards
Molecular alteration common in Myoepithelial Carcinoma of Soft Tissue
INI-1 deficiency (SMARCB1 deficiency) - confers a rhabdoid architecture, as does INI-1 loss in other entities
Immune profile in Myoepithelial carcinoma
Combinations or limited panels are most useful
Positive: CK5/6 (CKWSS too), p63, p40, S100 protein, GFAP, SOX-10, S100, calponin
Characteristic translocation for Synovial Sarcoma
X;18 –> SS18-SSX1 (more common) or -SSX2 (less common)
Synovial sarcoma, whether monophasic or biphasic, is characterized by this translocation
X;18 translocation…
Synovial sarcoma. Usual gene fusion is SS18-SSX1 (could be with SSX2)
t(2;13)…
PAX3-FOXO1 –> alveolar rhabdomyosarcoma
also PAX7 (3 is worse prognosis than 7)
PAX 7 is t(1;13)
t(7;16)…
FUS-CREB3L2 –> Low grade fibromyxoid sarcoma (LGFS)
t(X;17)…
ASPSCR1-TFE3 –> alveolar soft part sarcoma
H3F3 K36M immunohistochemical stain…
Chondroblastoma, which is a fairly common primary bone benign tumor. A positive stain is fairly sensitive and specific
K=Kondroblastoma
USP6 translocations….
primary ABC (aneurysmal bone cyst), if it’s a secondary feature next to a chondroblastoma, probably won’t have the gene rearrangements
t(16;17)(q22;p13), CDH11-USP6 fusion….
Primary aneurysmal bone cyst (definately remember USP6 gene translocations, but this is the most common partner)
what do nodular fasciitis, myositis ossificans, and ABC all have in common?
USP6 gene translocations
t(2;2)(p23;q13) RANB2-ALK fusion…
aggressive subtypes of pediatric inflammatory myofibroblastic tumors
t(4;19)(q35;q13) CIC-DUX4….
undifferentiated Ewing-like round cell sarcomas (these have aggressive behavior)
t(7;16)(q33,p11) FUS-CREB3L2….
LGFMS (low-grade fibromyxoid sarcoma)
inversion of chromosome 12 with NAB2-STAT6 fusion…
Solitary Fibrous Tumor (get STAT6 and CD34 on everything with spindled cells)
MDM2 in bone tumors…
MDM2 can be amplified in low grade osteosarcomas, both parosteal and central (though MDM2 in non-bone forming tumors is probably de-diff liposarc)
*don’t forget intimal sarcoma
Large, deep seated mass somewhere in the pelvic girdle (such as gluteus maximus muscle)
Look for INI-1 staining. If lost…epitheliod sarcoma, proximal type. Should be EMA and cytokeratin positive with CD34+ about 1/2 the time
TLE1 immunohistochemical stain positivity
synovial sarcoma (probably would get it on a poorly differentiated sample of synovial sarcoma)
Characteristic t(17;22)(q22;q13) leading to COL1A1-PDGFB fusion product….
DFSP (dermatofibrosarcoma protuberans)
CD99
Traditionally Ewing Sarcoma/PNET - but also mesenchymal chondrosarc! Ewing sarcoma/PNET exclusively shows a reciprocal translocation t(11,22)
Ewing sarcoma/PNET exclusively shows a reciprocal translocation….
t(11,22)
reciprocal translocation t(11,22)
Ewing sarcoma/PNET exclusively shows a reciprocal translocation t(11,22)
Extra target you can use for chondrogensis and therefore chondrosarc dx if you need it
Mesenchymal chondrosarcoma typically shows nuclear expression of Sox9, the master regulator of chondrogenesis.
What is Li-Fraumeni syndrome?
Li-Fraumeni syndrome (caused by an inherited mutant p53 allele) is associated with a greater risk of sarcomas (and other malignancies), in particular, a 500 times greater risk of osteosarcoma.
Inherited germline mutation of what allele gives you a 500x increased risk of osteosarcoma?
Li-Fraumeni syndrome (caused by an inherited mutant p53 allele) is associated with a greater risk of sarcomas (and other malignancies), in particular, a 500 times greater risk of osteosarcoma.
X;18 translocation leading to…
X;18 translocation leading to a fusion of the SYT gene (chromosome 18) and the SSX1 or SSX2 gene (chromosome X) is characteristic of synovial sarcoma. This translocation leads to the formation of the SYT/SSX1 or SYT/SSX2 chimeric transcripts diagnostic of synovial sarcoma.
SYT/SSX1 or SYT/SSX2
X;18 translocation leading to a fusion of the SYT gene (chromosome 18) and the SSX1 or SSX2 gene (chromosome X) is characteristic of synovial sarcoma. This translocation leads to the formation of the SYT/SSX1 or SYT/SSX2 chimeric transcripts diagnostic of synovial sarcoma.
Characteristic t(12;16) with FUS-DDIT3 fusion
Myxoid liposarcoma; thigh, never retroperitoneal primary
myxoid liposarc CAN (infrequently) have a …..with DDIT3?
EWSR1 (yes, that dumb gene)
CHOP and what gene are the same?
DDIT3 - myxoid liposarc
MDM2
chromosome 12, gene location
*don’t get it confused with the supernumerary ring form amplification
*liposarc
*osteosarc (low grade)
*intimal sarcoma
what do these have in common?
Li-Fraumeni syndrome
Beckwith-Wiedemann syndrome
Lynch syndrome
Multiple endocrine neoplasia type 1
Familial adenomatous polyposis
Carney complex
Neurofibromatosis type 1
adrenal cortical carcinoma
Positive for SF1, α-inhibin, melan-A, calretinin, synaptophysin
Negative for chromogranin, cytokeratins, EMA, CEA
adrenal cortical carcinoma IHC
differentiate by stains medulla and cortex in adrenal
chromo and melan-A and sf1