Two Rare Cases of Bronchus-Associated Lymphoid Tissue Lymphoma Successfully Treated with Rituximab-Bendamustine

The bronchus-associated lymphoid tissue (BALT) lymphoma is a rare subtype of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), affecting roughly 9% of all MALT lymphomas. The underlying pathomechanism of BALT lymphomas is not completely resolved and a standard of care treatment is so far not available.

Active surveillance of primary extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue

Although patients with bronchus-associated lymphoid tissue (BALT) lymphoma show an indolent clinical course, appropriate disease management at diagnosis is not well defined. This study aimed to compare 3 treatment strategies for patients with BALT lymphoma: active surveillance, systemic chemotherapy or immunotherapy at diagnosis, or complete surgical resection at diagnosis. We conducted a retrospective study of all patients with new diagnoses of marginal zone lymphoma (MZL) involving the lung who were treated at the Memorial Sloan Kettering Cancer Center between 1995 and 2017. Primary BALT lymphoma was defined as disease confined to the lungs and adjacent lymph nodes. Active surveillance was defined as a documented observation plan and ≥3 months of follow-up before initiating treatment. Overall survival (OS) and event-free survival (EFS) were compared between treatment groups. We reviewed 200 consecutive patients with MZL involving the lung; 123 met the inclusion criteria and were managed by active surveillance (47%), complete surgical resection (41%), or systemic chemotherapy or immunotherapy (11%). With a median follow-up of >60 months, surgical resection was associated with a superior EFS compared with active surveillance and systemic treatment (6-year EFS: 74% vs 65% vs 62%, respectively; P = .013). Larger lesions and thrombocytopenia were associated with shorter EFS. All groups had excellent OS at 6 years (93%), albeit with a slight superiority for surgical resection (100%) over active surveillance (91%) and systemic treatment (76%) (P = .024). BALT lymphoma is an indolent disease that can often be managed expectantly and not require therapy for many years.

Case Report: Bronchial associated lymphoid tissue lymphoma and Mycobacterium chelonae

Bronchial-associated lymphoid tissue (BALT) lymphoma is a rare condition that accounts for only 0.5-1% of all malignant lung tumours. We present the case of a 66-year-old man admitted with pneumonia for further study and therapy. Initially the sputum was positive for Mycobacterium tuberculosis complex using polymerase chain reaction technology and antituberculous therapy was initiated. Due to the lack of imagiological improvement, the patient underwent a pulmonary transthoracic biopsy that revealed BALT lymphoma. Months later, Mycobacterium chelonae was identified and specific therapy was started with clarithromycin and tobramycin, before initiating BALT treatment with cyclophosphamide. There are only a few documented cases of BALT lymphoma associated with Mycobacterium. In this case M. chelonae might have been present before BALT lymphoma, contributing as an immunologic stimulus, or appeared afterwards, in the neoplastic context. BALT has an indolent evolution with a good prognosis and that is the reason why some experts favour a “watchful waiting” option.

Early Bronchus-Associated Lymphoid Tissue Lymphoma Diagnosed with Immunoglobulin Heavy Chain Molecular Testing

When extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT), a low grade B-cell lymphoma, arises in the lung it is referred to as bronchus-associated lymphoid tissue (BALT) lymphoma. We describe a patient with a history of Sjögren’s syndrome and rheumatoid arthritis with dyspnea and imaging consistent with lymphoid interstitial pneumonia (LIP). However, while histology and immunohistochemistry lacked definitive features of a lymphoma, immunoglobulin heavy chain (IgH) polymerase chain reaction testing demonstrated B-cell monoclonality, consistent with an early BALT lymphoma.

Synchronous BALT Lymphoma and Squamous Cell Carcinoma of the Lung: Coincidence or Linkage?

A 72-year-old man presented with weight loss, fever, and malaise. Chest radiograph and CT revealed two large ill-defined masses in middle and left lower lobes. CT-guided biopsy of left lower lobe mass disclosed bronchus-associated lymphoid tissue (BALT) lymphoma. Middle lobe mass was considered second deposit in contralateral lung. The patient received chemotherapy for BALT. Followup CT disclosed regression of left lower lobe mass and stability of middle-lobe mass and of right paratracheal lymph nodes. CT-guided biopsy of middle-lobe mass revealed squamous cell lung carcinoma. Surgical biopsy of right paratracheal lymph nodes revealed malignancy. Disease was staged T3, N2, and M0. Combined chemotherapy for lung cancer and BALT lymphoma was initiated.