A case report of extranodal NK/T cell lymphoma nasal-type with direct pulmonary involvement

Rationale: Extranodal nasal-type NK/T-cell lymphoma primarily invades the nasal and nasopharyngeal regions, while direct pulmonary involvement is extremely rare and prone to clinical misdiagnosis or oversight. Patient concerns: A 45-year-old man presented with recurrent high fever and cough. Anti-infective therapy and the peaspartase + methotrexate + etoposide + dexamethasone regimen proved ineffective, with chest CT demonstrating disease progression. Diagnoses: A patient with extranodal nasal-type NK/T-cell lymphoma, classified as stage IV group B refractory category, predominantly presenting with lung infiltration and concurrent multiorgan involvement of the bone marrow and adrenal glands is described herein. Interventions: The disease was controlled only after timely adjustment to a gemcitabine combined with oxaliplatin + PD-1 inhibitor chemotherapy regimen. Outcomes: The patient now remains clinically stable with adequate oral intake and satisfactory sleep quality. Lessons: Clinicians should broaden diagnostic considerations and pay greater attention to heterogeneous tumors. For patients presenting with persistent recurrent fever, pulmonary consolidation lesions, and poor response to anti-infective therapy, prompt percutaneous lung biopsy should be performed to obtain pathological confirmation.