Fig. 2: Representative histology of salivary neoplasms reclassified as adenoid cystic carcinoma after identification of IGF1R hotspot non-frameshift insertions.

Tumors demonstrated basaloid cells with sharply demarcated matrix production, morphology compatible with adenoid cystic carcinoma. Cases included those with both IGF1R hotspot single nucleotide variants (panels A and C) and in-frame indel alterations (panels B and D).