A 33-year-old male patient who had cough and intermittent for two months was admitted to our clinic. He had experienced fevers, yellow sputum, episodes of minimal hemoptysis and left chest pain recently. He had no history of weight loss, alcohol abuse, or smoking, and didn't expose to tuberculosis. His respiratory examination revealed diminished movement of lower left chest wall. Other general clinical examination results were normal. However, laboratory findings revealed that the white blood cells, C-reactive protein, erythrocyte sedimentation rate (ESR) and procalcitonin (PCT) were all raised. The results of both T-SPOT TB test and tumor markers were negative. Cell immunity and humoral immunity were normal.
His chest CT showed bilateral consolidation in the right upper and middle lobes and the left upper lobes (Fig. 1A). There was a little left pleural effusion. No mediastinal or hilar adenopathy was noted. He was first treated for community-acquired pneumonia for three weeks, and all symptoms were gone. Further blood lab examinations on white blood cells, neutrophil, C-reactive protein, ESR and PCT were all normal. However, the chest CT scan revealed less pleural fluid and an unchanged consolidation (Fig. 1B). Some causes of non-resolving pneumonia should be excluded. We decided to complete other examinations.
The bronchoscopy revealed diffuse mucosal swelling in both lobar branches, with neutrophils and some normal bronchial cells, but no malignancies or acid fast bacilli were found; while other tests for microbes showed negative results. Pleural fluid was aspirated from the left hemithorax and identified as exudative. Cells in the pleural fluid were predominantly lymphocytes, with lactate dehydrogenase (LDH) 299U/L, adenosine deaminase level 45.2U/L. No malignant cells or acid fast bacilli were detected in the pleural fluid. PET-CT indicated intense fluorodeoxyglucose (FDG) uptake in the right upper and middle lobes and left upper lobe (maximum standardized uptake value: 5.66-9.63). There were no signs of disease in other sites.
Then an ultrasonic guided transthoracic needle biopsy of the right upper consolidated area was performed. H&E staining showed that normal alveolar structure had completely disappeared and had been substituted by diffuse lymphoid cells with irregular nucleus. These lymphoid cells included small round lymphoid cells, centrocyte-like cells and monocytoid-resembling lymphocytes (Fig. 2 A). Immuno-histochemistry cell staining showed positive results for CD20, CD79a, PAX-5, LCA, Bcl-2, and ki67 (LI about 10%) (Fig. 2 B, C and D), and negative results for CD5, CD23, CyclinD1, CD10, CD56, TdT, MUM1, CgA, Syn and NSE. These morphological changes match a diagnosis with extranodal marginal Zone B -cell lymphoma of mucosa-associated lymphoid tissue (MALT).
Furthermore, a bone marrow biopsy was performed and the results showed no neoplastic invasion. Leukemia immunophenotyping was normal. No Helicobacter pylori or other infections were found at gastroscopy. Therefore, this young male patient was diagnosed with Primary MALT lymphoma stage IE according to the Ann Arbor classification (Table 1).
The patient was treated with five cycles of chemotherapy, including cyclophosphamide, vincristine, adriamycin and prednisone and rituximab, and complained of no clinical symptoms. He came for clinical and radiological follow-up visits every three months; the consolidation decreased in his CT photograph. There have been no symptoms and no progression since then.