Silent imposter in pneumonic attire: primary pulmonary MALT lymphoma

Primary pulmonary lymphoma (PPL) is a rare extranodal lymphoma confined to the lungs, accounting for <1% of non-Hodgkin lymphomas. We describe a man in his early 30s presenting with progressive dyspnoea, fever and productive cough, initially treated as pneumonia. Despite multiple antibiotic courses, radiological lesions persisted. Histopathology and immunohistochemistry from transbronchial lung biopsy revealed extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. PET-CT confirmed localised pulmonary involvement, fulfilling criteria for PPL. The patient responded to rituximab-bendamustine chemoimmunotherapy with clinical improvement. This case highlights the importance of considering rare malignancies in non-resolving pulmonary consolidations.