Sinonasal NUT Carcinoma: A Call for Increased Attention to a Vital Clinical Diagnosis

Nuclear protein in testis (NUT) carcinoma is a highly aggressive and poorly differentiated carcinoma, defined by presence of NUT rearrangements in the NUTM1 (NUT midline carcinoma family member 1) gene. This tumor has a predilection for midline and paramidline structures of the upper aerodigestive tract and mediastinum and has a devastating clinical course, thus an early diagnosis is indispensable. However, due to its low incidence, this is often misdiagnosed by the clinicians and pathologists. Here, we report a case of NUT midline carcinoma of the nasal cavity in a 53-year-old man who presented with chief complaints of nasal discharge and obstruction, accompanied by blurring of vision and facial swelling. The present case report reviews the clinical characteristics, histopathological diagnosis of NUT carcinoma, highlighting the morphological and immunohistochemical findings and the pathological approach to sinonasal undifferentiated tumors encountered.