Ch 1 - Borderline thru

Question 1

What type of cells comprise a desmoid-type fibromatosis?

Answer 1

myofibroblastic cells

Question 2

What systemic condition is associated with desmoid-type fibromatosis?

Answer 2

Gardner syndrome (Familial colorectal polyposis) / FAP

Question 3

4 stains for desmoid-type fibromatosis?

Answer 3

1. vimentin (lol)
2. nuclear Beta-catenin (Valuable finding)
3. actins
4. desmin (occasional)

Question 4

What are the genetics behind syndromic and sporactic desmoid tumors?

Answer 4

Syndromic: APC gene for Gardner syn

Sporatic: CTNNB1 (beta-catenin)

Question 5

What stain might you use to separate a desmoid-type fibromatosis from another spindle cell neoplasm?

Answer 5

Beta-catenin can be valuable

Beta-catenin can also be positive in Glomangiopericytoma SFT, but STAT6 will distinguish

Question 6

Age, gender, location for a sinonasal glomangiopericytoma?

Answer 6

Female, 60s, unilateral nasal cavity

Question 7

Name that lesion: so-called patternless diffuse architecture, short fascicles, storiform, whorled, meningothelial, or reticular arrangements

Answer 7

glomangiopericytoma

Question 8

What have sinonasal glomangiopericytomas been found to have collision tumors with?

Answer 8

SFTs

Question 9

Positive stains for sinonasal glomangiopericytoma (5)

Answer 9

1. SMA (or MSA, but SMA better)
2. Nuclear Beta-catenin
3. Cyclin D1
4. Factor XIIIa
5. Vimentin

Neg:CD34, CD31, CD117, STAT6, BCL2, CK, EMA,Desmin, S100 (so ruling out NF, SFT, Leio, Etc)

Question 10

What is the genetic alteration for glomangiopericytoma?

Answer 10

CTNNB1 (nuclear beta-catenin)