Case report – Patient 2:
A 52-year-old male patient ex-smoker since 3 months (cumulative 30 pack/years) was admitted to our hospital in June 2020 presenting with dry cough since January 2020 and restricted physical resilience including dyspnea since April 2020. He denied B-symptoms. The laboratory evaluation revealed an isolated mild anemia with hemoglobin value of 11.4 g/dL (range, 13.5-17.5 g/dl) and an elevated C-reactive protein (CRP) of 86.45 mg/L (range, <5 mg/l. Chest X-ray showed bilateral infiltrates, particularly in the left lower lung. An antibiotic therapy with piperacillin/tazobactam was initiated with a decline of the CRP to 16.48 mg/L after 10 days of therapy. The first bronchoscopy with transbronchial biopsy revealed a highly florid and erosive inflammation with high-grade regenerative hyperplasia of the epithelium, which was CD20 and CD3 positive. The molecular clonality analysis detected immunoglobulin gene rearrangements of IGHA, IGHB and IGHC in 41, 278 and 146 base pairs, respectively. The subsequent CT scan showed still existing bi-pulmonary solid infiltrates in all lobes of the lung (Figure 3, Panels A and C). The suspicion of a BALT lymphoma was substantiated by further bronchoscopy with histopathology analysis showing a sub-mucosal stroma with B-cell containing infiltrates without a specific immunophenotype. A CT-based pulmonary biopsy confirmed a CD20 positive B-cell population without co-expression of CD5, BCL-2, CD10 or CD23 (Figure 4). Based on these results staging analysis containing bone marrow evaluation and extended CT scan were performed. Bone marrow histology showed no lymphatic infiltration. CT scan showed paraaortic, iliac and inguinal affected lymph nodes resulting in an Ann Arbor stadium IIIA.
A combined immunochemotherapy containing rituximab (375 mg/m2, day 0) and bendamustine (90 mg/m2, day 1-2) was initiated. The first cycle was well tolerated under standard supportive care without any serious adverse events or allergic reactions. During the hospitalization, the patient developed hypoxia at rest. Thus, he received oxygen up to 4 L/h via nose prongs. After the first cycle of immunochemotherapy, the unproductive cough improved and the oxygen therapy could be stopped. The immunochemotherapy was repeated every four weeks for in total six cycles; CT stagings were performed after three and six cycles. The intermediate CT scan showed no significant changes of the BALT lymphoma and the affected lymph nodes as compared to diagnosis. However, the clinical condition improved significantly. Therefore, the immunochemotherapy was continued. After six cycles a native CT scan was performed showing a reduction of the BALT lymphoma and normalization of the lymph nodes. Unfortunately, the patient denied a positron emission tomography–CT. According to the CT scan at least a partial remission (PR) was achieved (Figure 3, Panels B and D). Thus, maintenance therapy with rituximab is planned.