Natural Killer (NK)//T-Cell Lymphoma, Nasal Type, with Periorbital Involvement: A Case Report and Literature Review.

BACKGROUND Extranodal natural killer (NK)/T-cell lymphomas are rare neoplasms that result in the destruction of mid-facial tissues. Infrequently seen in ear, nose, and throat clinical practice, they are often misdiagnosed and treated as chronic sinusitis, which delays proper diagnosis. This study aimed to describe the insidious course of NK/T-cell lymphomas, nasal type. CASE REPORT A 36-year-old woman with a 2-year history of recurrent exacerbation of chronic sinusitis and allergies was admitted to our clinic. Multiple endoscopic sinus surgical procedures were performed. Repeated histopathological tissue examinations revealed extranodal NK/T-cell lymphoma, nasal type. Positron emission tomography combined with computed tomography (PET-CT) was performed to assess the extent of the disease. The patient was treated with antibiotics, steroids, and antifungal drugs for many months before the definitive diagnosis was made. The patient was eligible for modified SMILE chemotherapy; however, the patient died suddenly from septic shock several days before the beginning of treatment. CONCLUSIONS Chronic rhinosinusitis with progressive necrosis of sinonasal tissue that persists despite adequate antibacterial and antifungal treatment should prompt further investigation. In such cases, it is important to consider the diagnosis of NK/T-cell lymphomas, nasal type. Early diagnosis increases the opportunity for successful treatment.