Abstract
Human Papillomavirus-related multiphenotypic sinonasal carcinoma is a rare, and recently described neoplasm, defined by its association with high-risk Human Papillomavirus, which exclusively affects the sinonasal tract and simulates salivary gland tumors. Due to the infrequency of this neoplasm and the lack of knowledge of its pathological characteristics, it is susceptible to diagnostic error. We describe the clinical-radiological findings of a 54-year-old man with multiphenotypic sinonasal carcinoma related to Human Papillomavirus genotype 56. The diagnosis of multiphenotypic sinonasal carcinoma was suspected by light microscopy and was corroborated by immunohistochemistry and polymerase chain reaction (PCR) analysis. The patient was subsequently treated with 63.6 gray radiotherapies. He is currently alive after a follow-up of 20 months, with a recurrence of the disease. In conclusion, multiphenotypic sinonasal carcinoma is an unusual neoplasm, which is not well recognized and can be confused with adenoid cystic carcinoma. However, multiphenotypic sinonasal carcinoma should be included in the differential diagnosis as we encounter sinonasal tumors, which by histology present tubular, cribriform, and solid growth patterns, accompanied by dysplasia or carcinoma in situ in the superficial mucosa. In this case, it is necessary to perform immunohistochemistry for p16INK4A or PCR to confirm the presence of high-risk Human Papilloma Virus, which would confirm the diagnosis.