Extranodal NK/T cell lymphoma (nasal type) is a relatively rare malignancy. Because of its low overall incidence in the nasal sinuses, it is often under-recognized by many otolaryngologists, especially in primary care hospitals, where nasal type extranodal NK/T cell lymphoma is often misdiagnosed as sinusitis and delayed or treated incorrectly. Extra-nodal NK/T-cell lymphoma occurring in the nasal sinuses is a type of non-Hodgkin’s lymphoma, which is a kind of aggressive lymphoma, and the typical pathological manifestation is tumor cell infiltration and vascular destruction centered on blood vessels, so it is also called nasal vascular centered lymphoma. It often presents with swelling of the nasal mucosa, bleeding, increased secretion, followed by necrotic ulceration. In advanced stage, it may invade the orbit and nasal face, which may manifest as eye movement disorder, vision loss and nasal facial swelling; destroy the nasal septum and hard palate, resulting in perforation of nasal septum and hard palate; involve the pharynx, which may show pharyngeal ulcer and systemic symptoms such as sore throat, fever, restricted swallowing and wasting. The diagnosis of nasal extranodal NK/T-cell lymphoma relies on pathologic histology. However, nasal endoscopy often provides the basis for our diagnosis of nasal NK/T-cell lymphoma. CT and MRl scans are commonly used in clinical practice to determine malignant tumors such as nasal sinus lymphoma. Generally speaking, for stage III and stage IV nasal type extranodal NK/T-cell lymphoma, since the lesions go beyond the nasal cavity structure and cause destruction of nasal facial, orbital, skull base and hard palate structures, both otorhinolaryngologists and imaging physicians can be alerted to nasal sinus malignancies at an early stage and can be clearly diagnosed by pathological biopsy. However, many cases show that CT and other imaging examinations as well as nasal endoscopy may not be specific at the early stage, which may easily lead to missed diagnosis or misdiagnosis. It is not uncommon to misdiagnose nasal extranodal NK/T-cell lymphoma as chronic rhinosinusitis or fungal sinusitis, especially in primary care hospitals. Therefore, it is a very serious problem to master the CT and clinical manifestations of nasal extra-nodal NK/T-cell lymphoma and to detect nasal extra-nodal NK/T-cell lymphoma early. Stage I and II nasal type extra-nodal NK/T-cell lymphoma have atypical imaging manifestations, showing only nasal mucosal thickening and soft tissue shadow in the nasal cavity. The lesions are generally uniform in density, but due to the accumulation of necrotic tissue, indeterminate hypodense shadows can be seen within them, and the adjacent bone is often free of abnormalities or slightly damaged. Diffuse nasal type extra-nodal NK/T-cell lymphoma shows bone destruction in the midline of the nasal cavity with irregular soft tissue shadows, often spreading to the adjacent sinuses, and the lesions tend to invade the nasal septum, facial soft tissue, alveolar bone, hard palate, orbit, inferior temporal fossa, pterygopalatine fossa, etc. and show bone destruction and irregular soft tissue shadows in the corresponding areas, which are not necessarily connected with the nasal lesions. Therefore, the more frequent clinical misdiagnosis is limited nasal type extra-nodal NK/T-cell lymphoma. For patients with localized or extensive diffuse swelling of the nasal mucosa on nasal endoscopy and ineffective conservative treatment, if, with the progression of the disease, there is extensive swelling and necrosis of the nasal turbinate mucosa, indistinct structures in the nasal cavity, mucosal congestion, necrotic material on the surface, and easy bleeding, nasal type extra-nodal NK/T-cell lymphoma should be highly suspected and treated as early as possible after biopsy to confirm the diagnosis.