[Comparison of clinical characteristics between nasal cavity and sinus NK/T-cell lymphoma and diffuse large B-cell lymphoma].

<b>Objective:</b>To compare the clinical characteristics of nasal NK/T-cell lymphoma（NKTL） and diffuse large B-cell lymphoma（DLBCL） to improve the diagnosis and differential diagnosis of nasal lymphomas. <b>Methods:</b>A retrospective analysis of cases of nasal NKTL and DLBCL was conducted. The clinical symptoms, signs, and imaging features of both groups were compared and statistically analyzed. Results: The DLBCL group showed more symptoms like exophthalmos/diplopia and epiphora compared to the NKTL group （both <i>P</i>=0.040）. NKTL cases were more likely to be misdiagnosed as sinusitis（<i>P</i>=0.007）. In NKTL cases, nasal mucosal swelling（<i>P</i><0.01）, destruction of nasal structures（<i>P</i>=0.002）, and external nasal structural abnormalities（<i>P</i>=0.003） were more prevalent. In imaging, the DLBCL group more commonly demonstrated worm-eaten destruction of sinus bones （<i>P</i>=0.004）, sinus masses （<i>P</i>=0.018）, and invasion of adjacent structures including the pterygopalatine fossa, infratemporal fossa （<i>P</i><0.01）, orbit （<i>P</i>=0.039）, and skull base （<i>P</i>=0.011）. NKTL involved the turbinates（<i>P</i>=0.001）, nasal cavity and septum（<i>P</i>=0.016）, nasopharynx（<i>P</i><0.01）, and "skip" infiltration of external nasal tissues（<i>P</i>=0.042） more frequently. No statistically significant differences were found in other clinical features between the two groups. <b>Conclusion:</b>For patients with nasal obstruction and discharge, it is essential to inquire about systemic B symptoms, such as fever, and eye symptoms, such as periorbital swelling, diplopia, and lacrimation. Lymphoma should be suspected if local examination reveals diffuse nasal swelling, destruction of turbinates or septum, and external nasal structural abnormalities. Worm-eaten bone destruction and "cast-like" changes of the turbinates, septum, and nasal cavity, as well as "skip" infiltration of the external nose, are more common in NKTL. Sinus masses with invasion of the pterygopalatine fossa, infratemporal fossa, skull base, and orbit are more typical of DLBCL.