[A case of marginal zone B-cell lymphoma of the pulmonary mucosa-associated lymphoid tissue type].

Marginal zone B-cell lymphoma of the pulmonary mucosa-associated lymphoid tissue type (pulmonary MALT-MZL), a common kind of primary pulmonary lymphoma, is rare in pulmonary malignant tumors. One patient in our hospital was diagnosed by bronchoscope and the literatures on the subject were reviewed. The patient presented with periodical fever, cough and chest pain, and antibiotic therapy had no use. Chest CT scan showed the consolidation of right middle lobe and left lower lobe with CT angiogram signs, air bronchograms and distended bronchi. Pleural effusion in the left thorax mainly consisted of monocytes. Monoclonal protein was found in the electrophoresis of serum protein. Bronchial stenosis and swollen mucosa were seen with bronchoscope. The tissue section of transbronchial lung biopsy (TBLB) specimens showed diffusedly infiltrated small lymphocytes and a lymphoepithelial lesion. CD20 was positive and CD3, CD5, CD10, CD21, CD23, bcl2, bcl6 were negative in immunohistochemical stain. The clinical manifestations of pulmonary MALT-MZL are nonspecific and misdiagnosis is common, Appropriate invasive biopsy procedures are necessary for early diagnosis. Presentations such as periodical fever, distended bronchi in pulmonary consolidation, monoclonal protein might indicate diagnosis. Treatment includes surgical resection, radiotherapy and chemotherapy. Pulmonary MALT-MZL belongs to inert lymphoma and prognosis is relatively good.