Introduction: Sinonasal intestinal-type adenocarcinomas (ITACs) are rare and aggressive tumors, closely related to professional exposure to wood dusts or leather. Here we explored the role of non-coding RNAs controlling MUC2 in liquid biopsies and tumors from ITAC patients with the aim of identifying biomarkers and molecular mechanisms to improve early diagnosis, prognosis, and therapeutic approaches for this rare cancer. Methods: MiR-34c-3p, lncRNA AF147447 and MUC2 were measured in tumors and normal mucosa, in nasal washings (NW) from the affected and non-affected nostril and in plasma from 17 ITAC patients. The Apparent Diffusion Coefficient (ADC) was also evaluated by Magnetic Resonance Imaging. Results: MiR-34c was higher in ITACs compared to the corresponding normal mucosa (p = 0.021). Differentiated tumors exhibited higher miR-34c levels (p = 0.025) and lower ADC values (p