Sinonasal SMARCB1 (INI1) Deficient Carcinoma with Yolk Sac Tumor Differentiation: A Case Report and Treatment Options.

SMARCB1 (INI1) deficient carcinoma (SDC) is a newly-described, aggressive, high-grade malignancy of the adult population. Rarely, these tumors demonstrate yolk sac differentiation. Treatment protocols are not defined due to the rarity of this entity. A 55 year-old-male presented with a tumor originating in the maxillary sinus. He was treated with neoadjuvant therapy followed by radical surgery and adjuvant treatment. We review the literature and discuss the course of disease and treatments of sinonasal SDC with yolk sac tumor differentiation. To our knowledge, this is the sixth reported case of sinonasal SDC with yolk sac tumor differentiation. This is the first publication describing the clinical course and efficacy of therapeutic interventions.