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 (IGH) and T-cell receptor (TCR) rearrangements; and fluorescence in situ hybridisation (FISH) analysis of IGH, mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1), B-cell lymphoma 2 (BCL2), and myelocytomatosis (MYC) 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 IGH 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.