Salivary gland anlage tumor: molecular profiling sheds light on a morphologic question

Salivary gland anlage tumor (SGAT), previously described as a squamous proliferative lesion or "congenital pleomorphic adenoma," is a rare, benign entity that presents within the first months of life. It occurs almost exclusively in the nasopharynx or posterior nasal cavity and demonstrates a biphasic composition of epithelial and mesenchymal elements. Although the clinical and histologic features of SGAT are well described, its etiology remains poorly understood. SGAT is currently considered a hamartoma rather than a neoplasm, partly because of its benign behavior and lack of reported recurrence after treatment. However, investigators have not yet evaluated this concept by using genomic methods.

Here, we present 3 SGAT cases where we performed whole-exome sequencing.

Examination of sequence data, with specific attention to variants affecting 964 cancer-related genes, showed no plausible driver-type alterations.

The lack of apparent driver mutations supports the classification of this entity as a hamartomatous (nonneoplastic) process.