Sinonasal renal cell-like adenocarcinoma: a case report and literature review.

OBJECTIVE: Sinonasal renal cell-like adenocarcinoma (SNRCLA) is a rare sinonasal carcinoma that is easily misdiagnosed. We aimed to reveal clinical clinicopathological features, molecular genetic characteristics, treatment and prognosis of SNRCLA. METHODS : The pathological diagnosis and differential diagnosis of a case of SNRCLA and the literature was reviewed. RESULTS: Immunohistochemical analysis demonstrated positive expression of cytokeratin (CK)7, Sox-10, and carbonic anhydrase (CA)-IX, while negative expression was observed for CK20, CDX-2, Villin, Thyroid transcription factor(TTF)-1, Dog-1, Epstein–Barr virus viral capsid antigen (EBV-VCA), CD10,Renal cell carcinoma marker(RCC Ma), paired box(PAX)8, calponin, p63,and S-100. The positive proportion of Ki67 is less than 5%, and periodic acid-Schiff (PAS) staining confirmed glycogen content in the tumor cells. Epidermal growth factor receptor (EGFR) protein was overexpressed, but the EGFR gene was not mutated. The ETV6 gene was analyzed using fluorescence in situ hybridization (FISH) technology, but no rearrangement was detected. These mutations were detected using next-generation sequencing (NGS), including BRAF NM_004333:exon11 c.1357 C > G p.P453A, NM_000314:exon1 c.70_75del p.D24_L25del, MTOR NM_004958:exon39 c.5417 A > G p.H1806R, and PIK3CA NM_006218:exon5 c.1031T > G p.V344G. Following surgery and radiotherapy, no clinical or radiological evidence of recurrence or metastasis was observed during a follow-up period of 76 months. CONCLUSION: It is beneficial for diagnosis of SRCLC that clinical history, morphological characteristics and immunohistochemistry are combined. It is an indolent tumor, the potential for local recurrence requires individualized management and post-treatment surveillance. Meanwhile, It warrants further examination in molecular genetic characteristics.