Endobronchial Mucosa-associated lymphoid tissue (MALT) lymphoma: A diagnostic consideration

Endobronchial involvement of mucosa-associated lymphoid tissue (MALT) type lymphoma is a very rare entity and is often not included in the differential diagnosis when evaluating the patients with endobronchial lesions. Therefore, the diagnosis is usually difficult or delayed. The case here is an 82-year-old gentleman with history of prostate cancer and malignant melanoma who was incidentally found to have a right hilar soft tissue density around the lower lobe bronchus on a computerized tomography scan. Initial specimen of transbronchial needle aspirates of endobronchial lesion revealed monomorphic atypical cells, but was inconclusive for a definitive diagnosis. A second bronchoscopic examination with endobronchial biopsies and transbronchial needle aspiration submitted additionally for flow cytometric study revealed extranodal marginal zone B-cell lymphoma of MALT type. Although the diagnosis of pulmonary MALT lymphoma is reported to be of low diagnostic yield with bronchoscopic specimens and may require surgical biopsy in most cases, adequate specimen collection on bronchoscopy may suffice the diagnosis.