# Radiological features of sinonasal NUT (nuclear protein in testis) carcinoma: case series and systematic review

## TL;DR

This paper identifies specific radiological features of a rare and aggressive sinonasal cancer to improve early diagnosis and treatment.

## Contribution

The study provides a detailed analysis of imaging features of sinonasal NUT carcinoma through a systematic review and case series.

## Key findings

- Sinonasal NUT carcinoma commonly affects the ethmoid sinus and nasal cavity with heterogeneous enhancement on imaging.
- The tumor frequently shows invasive changes and extends to the orbit and intracranial regions.
- MRI reveals variable T2 signal intensities and necrotic areas in a significant proportion of cases.

## Abstract

NUT (nuclear protein in testis) carcinoma is a highly aggressive malignancy with poor prognosis, often leading to under-diagnosis due to limited recognition of its radiological features. This study aims to comprehensively analyze the radiological characteristics of sinonasal NUT carcinoma through a systematic review supplemented by institutional cases to facilitate early diagnosis and appropriate treatment planning.

A systematic review of MEDLINE, Scopus, and Embase databases was conducted following PRISMA 2020 guidelines to identify studies reporting CT and/or MRI features of sinonasal NUT carcinoma published up to May 29, 2024. Additional cases from our institution were included. Two board-certified radiologists with 15 and 18 years of experience jointly evaluated all images by consensus.

The study included 35 lesions from 35 patients (5 institutional, 30 from literature). Mean age was 37.3 years with equal sex distribution. The most commonly involved locations were ethmoid sinus (57.1%), nasal cavity (51.4%), and maxillary sinus (31.4%), with mean lesion diameter of 4.5 cm. On CT, all lesions demonstrated heterogeneous moderate enhancement, with calcification in 25.0% of cases. MRI revealed variable T2 signal intensities: mixed iso- and high signal (41.7%), high signal (33.3%), and mixed iso- and low signal (8.3%). Contrast-enhanced MRI showed heterogeneous moderate enhancement in 93.3% of cases. Necrotic areas were present in 48.1% of cases. Mean ADC value was 0.84 × 10⁻3 mm2/s. Invasive/destructive changes occurred in 91.4% of cases, with intraorbital extension in 52.9% and intracranial extension in 29.4%.

Sinonasal NUT carcinoma demonstrates characteristic imaging features including predilection for ethmoid sinus and nasal cavity, heterogeneous enhancement, and extensive invasive/destructive changes with frequent orbital and intracranial extension. While these features overlap with other sinonasal malignancies, recognition of these patterns may facilitate earlier diagnosis of this rare but highly aggressive tumor.