Quiz timePlease see the comments. #Breastpathology #pathology #frcp1 #pathboards #surgicalpathology

Identify the breast tumor

ETV6-NTRK3 Fusion is a result of which translocation?

What are the other tumors in which ETV6-NTRK3 fusion is expressed?

Also seen mostly in
1.congenital fibrosarcoma/ mesoblastic nephroma
2. Salivary gland - mammary analogue secretory ca

What is the most common IHC profile?

These tumors are mostly triple negative with ki67<20%. Rare cases with low ER, PR positivity are reported

Small molecule inhibitors (Larotrectinib & Entrectinib) that target NTRK3 & otherNTBK family members are recently developed & shows promising efficacy in the treatment of patients with TRK fusions. Hence identification of fusion is imp.

Select the most appropriate clinical presentation for this tumor

The tumor expresses polyclonal CEA, S100, mammaglobin, SOX10, MUC4 in strong and diffuse manner.

Picture Source
DOI:10.1007/s12105-013-0455-y