Results: Histologic examination revealed a biphasic proliferation of papillary stratified squamous and salivary ductal epithelia, both underneath the mucosal surface. Conclusion: In this unique case, as the classical SP, the tumour has a biphasic proliferation of squamous and ductal epithelia. However, unlike the classical SP, both epithelia grow under the mucosal surface. As a result, it didn't manifest as an exophytic proliferation, but as a nodule. We excluded squamous papilloma, inverted ductal papilloma, intraductal papilloma and mucoepidermoid carcinoma, the principal entities in the differential diagnosis of SP, and concluded it to be a SP with inverted pattern.