Lymphoproliferative lung disorders: a radiologic-pathologic overview. Part I: Reactive disorders

Area of Science:

• Pulmonary Pathology
• Immunology
• Radiology

Background:

• Normal lung lymphoid tissue includes intrapulmonary lymph nodes and bronchus-associated lymphoid tissue (BALT).
• Pulmonary lymphoid lesions are hypothesized to stem from aberrant BALT stimulation and response.
• These lesions represent a spectrum of lymphoproliferative disorders, ranging from reactive to neoplastic processes.

Purpose of the Study:

• To describe the spectrum of pulmonary lymphoid lesions.
• To differentiate between reactive and neoplastic lymphoproliferative disorders in the lung.
• To correlate imaging findings with these pathological entities.

Main Methods:

• Review of literature on pulmonary lymphoid lesions and BALT.
• Analysis of histopathological features of reactive lymphoid hyperplasia.
• Correlation of imaging characteristics (nodules, masses) with specific diagnoses.

Main Results:

• Reactive pulmonary lymphoid disorders are polyclonal and include conditions like nodular lymphoid hyperplasia and lymphocytic interstitial pneumonia.
• Affected patients are frequently asymptomatic.
• Imaging may reveal focal nodules, diffuse centrilobular nodules, or hilar/mediastinal masses.

Conclusions:

• Pulmonary lymphoid lesions encompass a range of conditions, primarily reactive, originating from BALT.
• Understanding the spectrum of these lesions is crucial for accurate diagnosis.
• Characteristic imaging findings can aid in identifying these pulmonary abnormalities.