The aim of the study was to evaluate microRNA expression in SMARCB1/INI1-deficient sinonasal carcinomas by means of polymerase chain reaction. A total of 4/56 (7 %) cases of SMARCB1/INI1-deficient carcinomas were detected among 56 sinonasal carcinomas using immunohistochemical screening.
The series comprised 3 males and 1 female, aged 27 - 76 years (median 64 years). All tumors arose in the nasal cavity.
Three neoplasms were diagnosed in an advanced stage pT4. During the follow-up period (range 14 - 122 months (median 72 months)), three tumors recurred locally and two patients died due to the tumor.
Microscopically, the tumors were composed of basaloid cells with variable component of rhabdoid cells with eosinophilic cytoplasm. All tumors showed upregulation of both miR-9 and miR-21 and downregulation of miR-145.
In summary, we described four cases of SMARCB1/INI1-deficient sinonasal carcinoma with novel findings on microRNA expression, which might be important for new therapeutic strategies in the future.