Novel Insights into the Characteristics of Poorly Differentiated Schneiderian Carcinoma: a Case Report

Low-grade papillary Schneiderian carcinoma is a poorly characterized disease in terms of molecular characteristics and treatment success. Here, we describe a case of poorly differentiated Schneiderian carcinoma with both p53 and p63 positive tumor and overexpression of miR-21that was successfully treated with a single intervention of right jaw hemiresection. A 61-year-old patient presented with nasal obstruction presented into the clinic. The CT imaging showed the presence of a Schneiderian papilloma in the posterior wall of the right maxillary sinus, with invasion to the right infra-temporal fissure. The histopathological and immunohistopathological revealed that the tumor belonged to the low-grade papillary Schneiderian carcinoma, an aggressive type of head and neck tumor. The decision was made to do a right jaw hemiresection. The resected specimen exhibit epithelial cells that had the growth pattern of inverted papilloma. The CT scanning done during post-operative follow-up found soft tissue in the anterior and lateral maxillary, but the biopsy revealed no presence of tumoral cells, only local inflammation. The immunohistochemistry analysis showed that the resected tumor tissue was p63+, CK7+, p16+, p53+, and Ki67+. The miRNA RT-PCR analysis on the resected tumor versus adjacent normal tissue revealed that miR-21 is overexpressed in tumor tissue, while miR-34a and miR-16 did not show any difference in expression. Our case description shows that even in case of aggressive Schneiderian papilloma molecular profile, the tumor spread is prevented by extending the surgery margins up to jaw hemiresection.