Sialadenoma papilliferum of the floor of the mouth with HPV Positivity: a rare case report and literature review.

Sialadenoma papilliferum (SP) is a rare benign salivary gland tumor characterized by a distinctive biphasic architecture and clinical resemblance to other papillary lesions of the oral cavity. Although recent studies have identified alterations in the MAPK pathway, particularly BRAF V600E mutations, the molecular landscape of this rare lesion remains incompletely characterized. We report a case of SP arising in the floor of the mouth of a 25-year-old male patient. Histopathological examination confirmed the diagnosis of SP, while immunohistochemical analysis revealed p63 positivity and negative staining for BRAF V600E and p16. Molecular analysis detected HPV-11 DNA by PCR-RFLP. To the best of the authors' knowledge, this is the first reported case of HPV-11 DNA detection in SP. Further studies are needed to clarify the biological significance of HPV detection and to better characterize the molecular pathways involved in the development of this rare lesion.