Primary extranodal NK/T-cell lymphoma of the lung: Mimicking bronchogenic carcinoma

Primary extranodal natural killer/T- cell lymphoma, nasal type (NK/TCL) in the lung is extremely rare and associated with Epstein-Barr virus (EBV) infection. An 80-year-old male presented with hemoptysis, which had lasted three days. Physical examination revealed inspiratory crackles at the left lung base and massive splenomegaly. Chest radiograph shows a mass-like lesion in the left lower lung but no active lesion six months earlier. Computed tomography demonstrated a soft tissue mass (size: 6.6 × 5.1 cm) with increased ground-glass opacities in the left lower lobe, several pulmonary nodules, and mediastinal lymphadenopathy. Transthoracic needle biopsy of the left-lower-lobe lung mass was performed. The pathology revealed atypical lymphoid cell infiltration, which is immunoreactive for cytoplasmic CD3, CD30 and CD56, but not reactive for CK and CD20. EBV-encoded RNA (EBER) was also detected in these atypical lymphoid cells. The serum EBV DNA level was 7.03 × 10(6) copies/mL and subtype 1 EBV was identified. No evidence of lymphoma involvement was found in the extrathoracic site. Primary pulmonary lymphoma showing nasal-type NK/T-cell subtype was diagnosed. Chemotherapy with cyclophosphamide and prednisolone was initiated immediately but the patient deteriorated and died three weeks later. In conclusion, patients presenting with rapidly growing lung mass and massive splenomegaly raise the possibility of aggressive pulmonary lymphoma. Extranodal NK/T-cell lymphoma with high baseline plasma EBV DNA levels signifies poor prognosis. Identifying young high-risk patients may have benefits for early aggressive and successful treatment.