INTRODUCTION
SMARCB1-deficient sinonasal carcinomas are locally aggressive rare malignant tumors of the nasal cavity and paranasal sinuses. They represent only about 1% of total head and neck malignancies.1,2SMARCB1-deficient sinonasal carcinoma is also called as integrase interactor-1 (INI-1) deficient carcinoma.2,3
It was first reported in 2014 and was described as a subset of sinonasal undifferentiated carcinoma.1,2,4Most of the cases are present lately when the condition is already locally aggressive at diagnosis. Probably, the reason for late diagnosis is due to the similarity of clinical symptoms to other benign conditions. As per our knowledge, only around 200 cases of SMARCB1 deficient sinonasal carcinomas have been reported so far in the medical literature and this is the first case that has been reported from Nepal.5
In this case report, we present a case of SMARCB1-deficient sinonasal carcinoma in a 54-year-old male with the lesion occupying the right ethmoid sinus and extending up to the right frontal sinus and nasal cavity.