Extranodal Marginal Zone Lymphoma: No Longer Just a Sidekick

Area of Science:

• Oncology
• Pulmonary Medicine
• Hematology

Background:

• The Oncology Grand Rounds series contextualizes clinical research for practical application.
• Extranodal marginal zone lymphoma (ENMZL) is a rare B-cell lymphoma that can occur in the lung.

Observation:

• A 51-year-old female presented for surgery, with imaging revealing a right lower lobe lung mass.
• Bronchoscopy and biopsy confirmed a low-grade lymphoma, immunophenotypically consistent with pulmonary ENMZL.
• The patient was asymptomatic, with staging revealing localized disease.

Findings:

• Pulmonary ENMZL was diagnosed based on morphology and immunohistochemistry (CD45+, CD20+, BCL2+, CD10-, CD5-, cyclin D1-, Ki-67 <5%).
• The patient's history included significant exposure to parrots.
• Staging confirmed stage I AE disease, localized to the chest.

Implications:

• This case highlights the importance of considering ENMZL in the differential diagnosis of pulmonary masses, especially with relevant exposure history.
• Early diagnosis and staging are crucial for appropriate management of pulmonary ENMZL.
• Understanding the clinical presentation and diagnostic pathway for rare pulmonary lymphomas aids in patient care.