ABSTRACT
BACKGROUND: Sinonasal teratocarcinosarcoma (SNTCS) is a rare and highly invasive neoplasm originating from the nasal cavity and sinuses. Typically, it exhibits an invasive behavior towards adjacent structures; however, in exceptional instances, it may infiltrate the intracranial compartment. Due to the tumor's rarity and lack of distinctive features on computed tomography (CT) and magnetic resonance imaging (MRI) images, SNTCS is often misdiagnosed. CASE SUMMARY: In this study, we present a case of SNTCS in a 56-year-old patient who exhibited unexplained cognitive impairment before admission. CT and MRI scans revealed the presence of a mass in the right nasal cavity, with lesions extending to the right ethmoid sinus and right frontal region. Subsequently, the patient underwent pathological examination for confirmation and received surgical intervention to excise the tumor. The future advancement in our understanding of this disease will significantly contribute to the precise diagnosis and treatment of SNTCS. CONCLUSION: SNTCS is an exceptionally rare malignant tumor that originates from the nasal cavity and paranasal sinuses, presenting a diagnostic challenge due to its non-specific imaging findings. MRI accurately delineates the location, morphological characteristics, size, internal structure, extent of surrounding involvement, and metabolic information of the lesion. These aspects play a pivotal role in the precise localization and qualitative assessment of SNTCS. Nevertheless, a definitive diagnosis still requires a pathological biopsy.