General Concepts

Question 1

What is the Carney Triad?

Answer 1

• Pulmonary chondroma
• Gastric stromal tumors
• Adrenal paragangliomas

Question 2

What is the difference between a pulmonary chondroid hamartoma and chondroma?

Answer 2

• Chondromas show no other mesenchymal elements such as fat, smooth muscle or fibrous tissue.
• Chondromas also do no show entrapped respiratory epithelium, unlike chondroid hamartomas.

Question 3

In what situations is ALK gene rearrangement most commonly identified, within lung primary tumors?

Answer 3

• ALK confers sensitivity to crizotinib (ALK inhibitor)
• ~ 5% of NSCLC harbor this mutation
• Frequently seen in light or never smokers
• Also seen in adenocarcinomas, especially those with signet ring histology
• Patients with ALK mutations tend to be about 10-15 years younger than those with ALK rearrangements.

Question 4

What is the main genetic alteration in solitary fibrous tumors?

Answer 4

• NAB2-STAT6 fusions with the overexpression of STAT6
• Also will be positive for CD34

Question 5

What is the incidence and relavence of KRAS mutations in lung cancers?

Answer 5

• mutations present in 10-30% of lung adenocarcinomas
• seen in all histologic subtypes
• most common mutation occurs as a single nucleotide substitution at codon 12

Note: KRAS and EGFR mutations are mutually exclusive and may confer resistance to EGFR tyrosine kinase inhibitors

Question 6

What are the markers that are positive in lung adenocarcinomas?

Answer 6

• TTF-1, Napsin A
• CK7, CEA
• MOC-31

Question 7

What are the markers that are positive in SCC of the lung?

Answer 7

• CK7
• CK 5/6
• MOC-31
• p63

Question 8

What are the positive markers associated with neuroendocrine carcinomas?

Answer 8

• CK7
• CD56 and CD57
• Chromogranin
• Synaptophysin