Sustained Clinical Response to Immunotherapy Followed by BET Inhibitor in a Patient with Unresectable Sinonasal NUT Carcinoma

Case report: Long term remission of metastatic sinonasal NUT carcinoma after palliative radiotherapy and immunotherapy in an elderly patient

NUT carcinoma (NC) is an extremely rare, aggressive malignancy characterized by chromosomal rearrangements in the NUTM1 (nuclear protein in testis) gene. It usually affects younger patients with a median age of diagnosis at 23 years old. The mainstay of treatment consists of combination chemotherapy, surgical resection, and high dose radiation. However, prognosis remains dismal with reported median overall survival of 6.7 months. Literature reporting on use of immunotherapy in head and neck NC is limited. Prolonged remission without aggressive multimodality therapy is rare. We report a case of a 87-year-old woman with metastatic sinonasal NC treated with palliative radiotherapy and pembrolizumab who achieved sustained response 2 years from diagnosis.

[Research Progress on Pathogenesis and Treatment of NUT Carcinoma]

NUT carcinoma (nuclear protein in testis carcinoma) is a rare and highly invasive malignant tumor, which is most common in midline organs and lungs. The characteristic genetic change of NUT carcinoma is the rearrangement of NUT middle carcinoma family member 1 (NUTM1) gene. In this article, we will review the pathogenic mechanism of its most common fusion form, bromodomaincontaining protein 4 (BRD4)-NUTM1 fusion gene, and the progress in the research and development of targeting drugs.
.

Placental metastasis from maternal NUT carcinoma: diagnostic pitfalls and challenges

We report a young pregnant woman with large midline thoracic mass and markedly elevated serum alpha-fetoprotein (AFP) levels. Initially suspected as a germ cell tumour (GCT) due to age, site, and high AFP levels, a biopsy unveiled a high-grade malignant tumour characterised by undifferentiated monotonous cells. Although tumour cells exhibited positive AFP, the overall immunoprofile did not provide additional evidence to support GCT. Further work-up showed positive for NUT (nuclear protein in testis) immunostaining and the presence of BRD4-NUT1 fusion, confirming the diagnosis of NUT carcinoma. On radiology, there were extensive metastases to lungs, liver, vertebrae, and placenta. Despite aggressive chemotherapy, radiotherapy and immunotherapy, she did not respond to the therapies. Fortunately, her child was not affected by the carcinoma. This is the first case highlighting that thoracic lung primary NUT carcinoma can spread to the placenta and manifest with elevated serum AFP levels, potentially leading to misdiagnosis as GCT both clinically and pathologically.