Adult sialoblastoma harbouring FGFR2 p.C382R gene mutation

Sialoblastoma is a rare salivary gland malignancy with most cases described in pediatric population. Adult presentation is rare, with only three cases reported to date in English literature. Recent molecular studies have identified recurrent activating FGFR2 p.C382R mutations in a subset of sialoblastomas, which appear to define a molecularly distinct group and may be associated with more aggressive behaviour. We report a basaloid parotid gland neoplasm in a 57-year-old man. The tumour showed solid basaloid morphology, high proliferative activity, and an immunophenotype overlapping with high-grade basaloid salivary gland carcinoma. Comprehensive molecular profiling identified FGFR2 p.C382R as a likely oncogenic driver, with no recurrent salivary gland fusion events detected. This case expands the limited literature on adult sialoblastoma and highlights the need to consider sialoblastoma in the differential diagnosis of basaloid salivary gland neoplasms in adults.