[Analysis of imaging features of rare tumors in nasal cavity and paranasal sinus]

Objective:To explore the imaging features of rare tumors of nasal cavity and sinuses, and to improve the understanding of these diseases, thereby aiding clinical diagnosis and treatment. Methods:The CT and MRI findings of 79 cases of rare neoplasm of nasal cavity and sinuses confirmed by pathology were retrospectively analyzed, and the imaging features were summarized. Results:Among the 79 cases, there were 16 cases of neuroendocrine carcinoma, most showing expansive and infiltrative bone destruction without hyperosteogeny and sclerosis. The sphenoid sinus exhibited a "pigeon" shape. In 28 cases of malignant melanoma, MRI signals were diverse, typical signals were rare, but mixed signals were more common. In 12 cases of rhabdomyosarcoma, MRI enhancement mostly showed "grape-like" enhancement and partial ring enhancement; There were 10 cases of olfactory neuroblastoma, the lesions were consistent with the distribution area of olfactory mucosa, most of them were lobulated, marginal nodules, and "flower ring" enhancement, and 2 cases grew across intracranial and external, with multiple cystic lesions and surrounding flaky edema bands. In 5 cases of solitary fibrous tumor, Benign tumors had regular shape and uniform density, while malignant tumors had irregular shape and uneven density, The enhancement was obviously uneven and showed a "pattern" change. There were 2 cases of sarcomatoid carcinoma, both with lobed appearance, uneven density, lamellar low-density shadow, and osteolytic bone destruction. In 4 cases of schwannoma, the enhancement showed obvious inhomogeneous enhancement. One case showed cystic necrosis, one case showed calcification, and the surrounding structure was compressed without damage. There was 1 case of neurofibroma, with many cystic components, low signal separation and compartmentalized enhancement. One case of paraganglioma showed moderate enhancement in the arterial phase and progressive enhancement in the venous phase, accompanied by significant swelling bone destruction. Conclusion:Rare tumors of nasal cavity and paranasal sinuses have distinctive imaging features. CT and MRI can effectively show the extent of the lesions and the degree of infiltration into adjacent tissues and organs, which is helpful for early clinical diagnosis and staging. However, definitive diagnosis still depends on pathology and immunohistochemistry.