Specific molecular characteristics of Tumors (not soft tissue) Flashcards
NR4A3 fusion/activation
Acinic Cell Carcinoma
*also DOG1
The majority of cases have t(4,9) resulting in NR4A3 upregulation
Acinic Cell Carcinoma
*also DOG1
t(4;9)
Acinic Cell Carcinoma
*also DOG1
Salivary gland; acinic cell carcinoma; molecular
The majority of cases have t(4,9) resulting in NR4A3 upregulation
Secretory Carcinoma
secretory carcinoma harbor ETV6::NTRK3 fusion
t(12;15)(p13;q25)
Salivary gland; secretory carcinoma; molecular
secretory carcinoma harbor ETV6::NTRK3 fusion
t(12;15)(p13;q25)
CRTC1::MAML2 fusion is seen in 40-90% of….
mucoepidermoid carcinoma
mucoepidermoid carcinoma; molecular
CRTC1::MAML2 fusion is seen in 40-90%
MYB fusion /activation is seen in 80% of…
adenoid cystic carcinoma
adenoid cystic carcinoma; molecular
MYB fusion /activation
Gains (especially trisomy) of chromosome 7, 17 and loss of Y chromosome
Papillary RCC (foam cells, look for tubulopapillary features)
Papillary or tubule-papillary architecture, lined by cuboidal cells (low-grade tumors); cells can have abundant basophilic, eosinophilic, clear +/- cytoplasm, hemosiderin pigment –> FOAM CELLS
Papillary RCC (2nd most common RCC)
Gains of chromosome 7, 17 and loss of Y chromosome,
*while majority unilateral, these of all RCCs are most inclined to be b/l and multifocal
Stains for Papillary RCC
- IHC: Positive: PAX8, CK7 (but negative in eosinophilic tumors), AMACR, vimentin, CD10, FH; Negative: CAIX (can be focal positive)
- Gains of chromosome 7, 17 and loss of Y chromosome,
MET germline mutation and kidney
Papillary RCC
don’t forget the Gains of chromosome 7, 17 and loss of Y chromosome,
t(6;9)(q22-23;p23-24) …salivary gland….
Adenoid Cystic Carcinoma
MYBL1-NFIB fusion → t(6;9)(q22-23;p23-24)
PLAG1-HMGA2 fusion…
pleomorphic adenoma
PAX8/PPAR gamma rearrangement, a translocation (2;3)(q13;p25)
This is the second most common mutation found in follicular carcinomas, being present in approximately 30% of follicular carcinomas and approximately 5% of oncocytic (Hurthle cell) carcinomas.
Thyroid and RAS mutations
These are the most common somatic mutations found in follicular thyroid carcinoma.
RET/PTC1 and PTC3 rearrangements on chromosome 10 (10q11. 2)
This is the second most common molecular abnormality seen in papillary thyroid carcinomas (PTC), being present in approximately 20% of cases.
TRK rearrangement of the NTRK1 gene of chromosome 1q22
This rearrangement is found in less than 5% of PTCs.
Thyroid and BRAF.
Point mutation in the BRAF gene at codon 600 (BRAFT1799A [V600E])
BRAF mutations are the most commonly detected abnormality in PTC, present in around 45% of adult cases. Ninety percent of these mutations show Valine to Glutamate point mutation BRAFT1799A (V600E).
granulomatous stuff on cytology of a lymph node…
If not medical…
Squamous cell carcinoma, seminoma, and thymoma are the most common metastatic tumors associated with granuloma formation in lymph nodes. Granulomas may also be found in lymph nodes harboring primary or secondary malignant diseases, including Hodgkin lymphoma and T cell-type non-Hodgkin lymphoma.
Molecular analysis often shows mutations of SMAD4 and KRAS genes
KRAS mutations are present in 95% of pancreatic adenocarcinomas. Mutation of SMAD4 (DPC4) is also seen.
Atrial myxoma has been linked to which gene?
Atrial myxoma has been linked to the PRKAR1-alpha gene.
80% of SPORADIC colorectal carcinomas have what mutation?
APC.
This is why a germline mutation in APC has 100% chance of colon cancer
*normally, APC product inhibits WNT pathway (B-catenin)
*a mutation of APC will result in abnormal B-catenin nuclear localization
*this is the CHROMOSOMAL instability pathway
10-15% of SPORADIC colorectal carcinomas are NOT related to some APC mutation…which mutations are these carrying?
somewhere in the hMLH1 realm
*95% are MLH1
*more rarely seen are MSH2 and MSH6
MOST rare: PMS2
If you lose MLH1 by IHC, what does that mean?
*you have more work to do
*MLH1 loss alone (and then it’s dimer) can happen in sporadic tumors
*MSH2, MSH6 and PMS2 loss are essentially lynch diagnostic
If you lose MSH2, MSH6 orPMS2, what does that mean?
*MSH2, MSH6 and PMS2 loss are essentially lynch diagnostic
*MLH1 loss alone (and then it’s dimer) can happen in sporadic tumors
KRAS mutations in a colorectal carcinoma…
EGFR-targeted antibody therapy
*RAS mutations confer resistance to this therapy
*bad prognosis
*Cetuximab