Squamous cell carcinoma as a somatic-type malignancy in an extragonadal immature teratoma of the sinonasal region.

Somatic-type malignancy arising in a teratoma of the sinonasal region is extremely unusual, creating a diagnostic dilemma. There are no definite guidelines for management of such cases. A 15-year-old male with a maxillary mass was misdiagnosed as angiomyolipoma, maxillary carcinoma, mucoepidermoid carcinoma, and teratocarcinosarcoma, followed by the final diagnosis of squamous cell carcinoma arising in an immature teratoma. He received neoadjuvant chemotherapy, followed by surgery and chemo-radiotherapy, and is disease-free at 21 months. This case highlights the difficulty faced when diagnosing neoplasms unusual to the head and neck region, particularly on small biopsies, and good outcome following appropriate multimodality management.