Malignancies arising in oncocytic schneiderian papillomas - A report of 2 cases and review of the literature

oncocytic schneiderian papillomas (OSPs) are uncommon benign neoplasms that arise from the sinonasal schneiderian epithelium. Malignancies arising in OSPs are rare, and, to our knowledge, only 14 such instances have been repo rted in the medical literature. We report 2 additional cases-a small cell c arcinoma and a sinonasal undifferentiated carcinoma arising in OSPs and pre senting synchronously with the benign neoplasm. The potential for malignant transformation in OSPs is small, but warrants that these papillomas be com pletely excised to exclude a coexisting carcinoma.