Definition of Carcinoma, NUT Midline

Carcinoma, NUT midline: This is an older term for a cancer now referred to as NUT carcinoma. NUT carcinoma is a rare and very aggressive form of cancer that forms along midline structures of the body such as the head, neck, or lungs. The tumor cells have the appearance of a poorly differentiated squamous cell carcinoma. NUT carcinoma contains a specific genetic mutation known as a fusion oncogene, which occurs by joining parts of two different genes together. With NUT carcinoma, the NUT gene is joined to another gene (most commonly the BRD4 gene, but in some cases BRD3, NSD3, or other genes). Diagnosis of the tumor requires identification of this abnormal fusion gene. The exact cause of NUT carcinoma remains unknown.