ABSTRACT
Sialoblastoma is a rare epithelial tumor of the salivary glands with an uncertain potential for malignancy, which typically affects children. A 20-days-old female child was referred to the Department of Maxillofacial Surgery due to the presence of a large mass localized at the left lateral cervical region, near the mandibular angle. The physical and instrumental examinations revealed a large nodular mass occupying almost completely the left neck.
The patient was submitted to surgery and the neoplasms was excised “en bloc”. Histological examination showed a neoplastic proliferation of basaloid cells predominantly organized in solid nests.
Immunohistochemistry study displayed expression of Pan Keratin and p63 with a Ki-67 homogeneous staining in about 20% of tumor cells. The prognostic role of Ki-67 proliferation index has been suggested with low value (<5%) associated with a good prognosis without disease recurrence.
Through this case and the review of the literature we try to establish the state of the art regarding the clinical aspects, the morphological and immunophenotypic features for diagnostic purpose. Moreover, we asses which parameters can influence the prognosis, paying attention especially to the cases of sialoblastoma diagnosed in the first year of life.

IMPACT STATEMENT
The case we presented demonstrates that rare masses in newborns can be challenging to diagnose due to their rarity, but in this clinical context, they are expected to have a favorable prognosis.