[A case of primary pulmonary B cell lymphoma confirmed by gene analysis]

Area of Science:

• Pulmonary Medicine
• Hematology
• Oncology

Background:

• Distinguishing benign lymphoproliferative disorders from malignant lymphomas in the lung can be challenging.
• Early and accurate diagnosis is crucial for appropriate patient management and treatment.

Observation:

• A 76-year-old man presented with a right middle lung coin lesion.
• Initial transbronchial biopsy suggested a lymphoproliferative disorder, leading to a diagnosis of pseudolymphoma after lobectomy.
• Immunoperoxidase studies were inconclusive for a neoplastic monoclonal process.

Findings:

• Genetic analysis of immunoglobulin heavy chain (JH) genes revealed a rearranged band.
• T-cell receptor beta-1 (TCR beta-1) gene rearrangement was absent.
• These genetic findings led to a revised diagnosis of B cell lymphoma, overriding the pseudolymphoma diagnosis.

Implications:

• Genetic analysis, particularly immunoglobulin gene rearrangement, is essential for differentiating B cell lymphoma from pseudolymphoma.
• Accurate molecular diagnostics can refine lung cancer diagnosis and guide therapeutic strategies.
• This case highlights the importance of integrating histopathology with molecular techniques for definitive diagnosis.