Molecular analysis of bronchoalveolar lavage fluid to assist pulmonary lymphoma diagnoses.

[BACKGROUND] Diagnosing pulmonary lymphoma is challenging and often requires surgical procedures. Molecular analysis of bronchoalveolar lavage fluid (BALF) may facilitate pulmonary lymphoma diagnosis; however, many aspects of this technique remain unknown. We aimed to establish a molecular diagnosis strategy for pulmonary lymphomas using BALF.

[METHODS] The following molecular analyses were performed using BALF from 62 patients (eight with adult T-cell leukaemia/lymphoma (ATLL) and 11 with B-cell lymphoma): flow cytometric analysis; T-cell and B-cell clonality based on immunoglobulin heavy chain () and T-cell receptor () rearrangements; and fluorescence hybridisation (FISH) analysis of , mucosa-associated lymphoid tissue lymphoma translocation gene 1 (), B-cell lymphoma 2 (), and myelocytomatosis () oncogene.

[RESULTS] CD25 and tumour suppressor in lung cancer-1 marker levels were significantly elevated in ATLL cases at a median of 37.8% and 33.0%, respectively, with 100% positive TCR rearrangements. Notably, FISH analysis showed numerical chromosomal abnormalities in at least one of the genes in 87.5% of patients. In B-cell lymphoma, CD19 and CD20 marker levels were significantly elevated at 4.2% and 14.3%, respectively. The sensitivity and specificity of rearrangements were 81.8% and 85.4%, respectively. FISH analysis detected translocations in at least one of the genes in 45.5% of patients.

[CONCLUSIONS] Numerical chromosomal abnormalities in the BALF of patients with ATLL and gene translocations in B-cell lymphoma are specific and novel findings. Molecular analysis of BALF is expected to be incorporated into a diagnostic system for pulmonary lymphoma to achieve low invasiveness and improve diagnostic accuracy.