Pulmonary extranodal natural killer/T-cell lymphoma: clinical presentation, CT characteristics, and patient outcomes

Background: Due to the extreme rarity of pulmonary extranodal natural killer/T-cell lymphoma (ENKTCL), studies on this lymphoma type are limited. We aimed to investigate the clinical presentations, computed tomography (CT) findings, CT dynamic changes, and outcomes of patients diagnosed with pulmonary ENKTCL. Methods: We conducted a retrospective cohort study on ENKTCL, nasal type, at West China Hospital, from January 2010 to January 2023. Out of 27 initial cases with pulmonary ENKTCL, we excluded 4 due to the lack of chest CT images, resulting in a final cohort of 23 patients. Our evaluation covered clinical features, laboratory findings, CT presentations, treatment strategies, and survival outcomes. Survival analyses were performed using the Kaplan-Meier method, with log-rank tests for survival curve comparisons. Given the small sample size, our interpretation of the data is mainly descriptive. Results: The most common CT presentations in our institution was solitary or multiple nodules (7/23, 30.4%). The halo sign (78.3%) and floating vessels sign (83.3%) were commonly observed in pulmonary ENKTCL. Elevated lactate dehydrogenase (LDH) levels were observed in 20 (86.9%) patients. The median overall survival (OS) for pulmonary ENKTCL patients was 1 month; 3 cases displayed a favorable prognosis, maintaining complete remission (CR) status for 1.5-7 years after receiving chemotherapy. Chemotherapy led to improved prognosis, with a median survival of 5 months seen in patients who received chemotherapy. Patients with bilateral lung involvement had worse outcomes compared to those with unilateral lesions. Conclusions: Pulmonary ENKTCL is a rare and aggressive disease, often misdiagnosed due to nonspecific clinical and CT features. Laboratory tests, failure of antibiotic treatment, and "floating vessels sign" on enhanced CT scans may aid in diagnosis. Timely chemotherapy may improve survival, emphasizing the importance of early detection and prompt treatment.