T-cell and NK-cell lymphomas in the lung.

While the lung is frequently involved by systemic lymphoma, primary pulmonary lymphoma accounts for less than 1% of all extranodal ymphomas. In particular, T-cell lymphoma is very rare in the lung, as a primary or secondary lesion. Patients with pulmonary T-cell lymphoma usually present with cough, dyspnea, pain, fever, recurrent infections, and hemoptysis. Typical radiologic features include pulmonary nodules, consolidation, solid pulmonary opacities, cystic changes, hilar adenopathy, and pleural effusions. Patients with these clinical and radiologic findings are frequently presumed to have pneumonia and initially treated with empirical antibiotics. Therefore, CT-guided needle biopsy, bronchoscopic examination, or even wedge biopsy should be considered when clinical symptoms show deterioration despite adequate antibiotic therapy. Precise pathologic diagnosis and molecular characterization are recommended in all cases, following the World Health Organization (WHO) classification. Principles of treatment typically vary with the different histologic types of T-cell lymphoma.