Laryngeal NUT Carcinoma With BRD4::NUTM1 Fusion: A 4-Year Clinical Course Highlighting the Limitations of Current Multimodal Therapy.

BACKGROUND: Nuclear protein in testis (NUT) carcinoma is a rare, aggressive malignancy driven by NUTM1 rearrangement, often misdiagnosed as squamous cell carcinoma, with no established standard therapy. This report describes the clinical course and treatment resistance in primary laryngeal NUT carcinoma and provides insights into potential mechanism-based therapeutic approaches. CASE: A 30-year-old man with a laryngeal tumor was initially treated for poorly differentiated squamous cell carcinoma. Recurrent disease prompted re-evaluation; NUT carcinoma was diagnosed by NUT immunohistochemistry, and the BRD4::NUTM1 fusion was confirmed by molecular analysis. A bromodomain and extra-terminal (BET) inhibitor and alternating vincristine, doxorubicin, and cyclophosphamide (VDC)/ifosfamide and etoposide (IE) chemotherapy induced transient tumor regression, whereas vorinostat, immune checkpoint inhibitors, and other systemic therapies were ineffective. Disease progression was ultimately driven by uncontrolled locoregional recurrence. Autopsy revealed a massive infiltrative tumor with extensive locoregional invasion, whereas distant metastatic disease was limited to minute pulmonary nodules; death resulted from overwhelming infection secondary to uncontrolled locoregional progression rather than systemic metastasis. CONCLUSION: Early molecular diagnosis and biologically informed multimodal strategies are essential for managing laryngeal NUT carcinoma and overcoming treatment resistance.