A Novel Successful Case of Nasal and Sinus Yolk Sac Tumor With SMARCB1 (INI-1) Deficiency: A Case Report

Yolk sac tumors (YSTs) of the head and neck region account for only 1% of all malignant tumors of germ cell origin. YSTs with SMARCB1 deficiency are very aggressive. Only one nasal and sinus YST with SMARCB1-deficient carcinoma (SDC) was reported with follow-up information but the patient died 20 months after diagnosis. We report a successful case treated by surgery combined with radiotherapy and limited cycles of chemotherapy, achieving a good prognosis. A 55-year-old male was seen with a three-month history of right nasal congestion, right nasal hemorrhage and hyposmia. The tumor widely invaded multiple regions such as the sphenoid, ethmoid sinus, orbital medial wall, choana, right maxillary sinus, and right pterygopalatine fossa. After endoscopic surgery, he was diagnosed as SDC with pure YST differentiation. The patient underwent endoscopic surgery, combined with radiotherapy as well as three cycles of chemotherapy with etoposide and cisplatin (EP regimen) and finally achieved over one year of disease-free survival. YST with SDC in the nasal and sinus regions is very rare and hard to treat. We highlight the value of combined treatment options including surgery, radiotherapy and limited cycles of chemotherapy to achieve a good prognosis.