NUT midline carcinoma (NMC) is a rare and aggressive disease encountered in the midline of the head and neck or mediastinum. Due to its sparse incidence and subtle pathologic features, we aim to increase knowledge and awareness for this pathologic entity. We present an exemplary case of a young, healthy male presenting with oral cavity pain and cervical lymphadenopathy. This patient was initially diagnosed with an unspecified, highly aggressive sublingual gland malignancy and underwent locoregional resection with free flap reconstruction however suffered a rapid local recurrence and widely extensive metastasis within just 1 month. After rigorous analysis, final pathologic diagnosis revealed a poorly differentiated carcinoma with evidence of squamous differentiation that eventually, post-mortem tested positive for NMC. Only one prior case of sublingual gland NMC has been previously reported as we discuss the literature regarding all sublingual gland malignancies as well as the pathologic features and treatment options for NMC. We recommend consideration of testing for the NUT proto-oncogene at the time of biopsy in the clinical setting of a poorly differentiated midline carcinoma, especially with squamous differentiation, of the head or neck in order to identify patients for clinical trial enrollment and appropriately counsel on the poor clinical prognosis. Improving clinician awareness is critical to increase diagnostic accuracy and need to study prospective treatment outcomes as the first step toward improving management of this difficult disease.
Keywords: Floor of mouth; Head and neck cancer; Oral cancer; Sublingual salivary gland; Undifferentiated carcinoma.