Imaging and clinical features of NUT gene-related carcinoma in the nasal cavity and sinus / 中华放射学杂志

ABSTRACT

Objective:To assess the clinical and imaging features of NUT gene-related sinonasal carcinomas (NUT midline carcinome).Methods:The clinical data and pretreatment imaging findings of 5 cases with pathologically proven NUT sinonasal carcinomas were analyzed retrospectively in Beijing Tongren Hospital, Capital Medical University from January 2016 to December 2020. Of 5 cases, the tumors affected 4 females and 1 male with an age range of 15 to 48 years (median 19 years). Clinical data of all cases were available before surgery with both CT and MR examination. Tumor location, CT density, boney change, calcification, tumor size, T 1WI, T 2WI and diffusion weighted imaging (DWI) signal intensity, appearance diffusion coefficient (ADC), type of time intensity curve (TIC) of dynamic contrast-enhanced (DCE)-MRI were evaluated. Results:All five cases belonged to T4 stage of the clinic TNM system. The locations were nasal cavity ethmoid, sphenoid and maxillary sinus ( n=1), nasal and maxillary sinus ( n=1), nasal cavity and ethmoid sinus ( n=3). Iso-attenuated in 3 cases, heterogeneous with local necrosis in 2 cases, and heterogeneous with calcification in 3 cases on CT imaging. Bone erosion was found in 4 cases, and bone erosion with destruction in 1 case. The tumor sizes ranged from 4.2 to 4.9 cm (median 4.5 cm) on MR axial imaging. On T 1WI, 5 cases showed isointense compared with adjacent temporal muscles, with focal hypointense in 2 cases. On T 2WI, the tumor was graded as isointense in 3 cases, and hyperintense in 2 cases. Heterogeneous enhancement in all cases with mild in 3 cases, and moderate in 2 cases on postcontrast MR imaging. On DCE-MRI of 5 cases, there were 3 cases of type Ⅲ (washout-shaped curves), and 2 cases of type Ⅱ of the TIC (plateau-shaped curves). The range of ADC values was from 0.63×10 -3 to 1.17×10 -3 mm 2/s, and median ADC value was 0.84×10 -3 mm 2/s, of 5 cases with varying degrees of high signal on DWI. The Ki-67 index ranged from 30% to 80% of the tumor. An immunohistochemical study showed that the tumor cells of 5 cases were all positive for both NUT and INI-1 genes. One case was performed with biopsy and followed by chemotherapy, four cases were performed with surgery, combined with the following chemotherapy, and one also was implemented with radiation therapy. The follow-up time was 7-16 months. Five cases were all alive during the follow-up. Conclusions:The NUT midline sinonasal tract carcinoma is a rare, gene-related solid malignant tumor. The tumor is more commonly seen in young patients, mostly centered in the nasal and ethmoid region with invasive growth, more calcification on CT, and heterogeneous enhancement on MRI. These findings are some characteristics of the tumor.