Pulmonary Nodular Lymphoid Hyperplasia.

Area of Science:

• Pulmonology
• Pathology
• Oncology

Background:

• Pulmonary nodular lymphoid hyperplasia (PNLH) is an uncommon reactive lymphoproliferative disorder.
• It typically presents as an asymptomatic lung mass, posing diagnostic challenges.
• Morphologic overlap exists with extranodal marginal zone lymphoma and IgG4-related sclerosing disease.

Purpose of the Study:

• To review the clinicopathologic features of PNLH.
• To contrast PNLH with its histopathologic mimickers.
• To aid in the accurate diagnosis of PNLH.

Main Methods:

• Review of existing literature on PNLH and its differential diagnoses.
• Analysis of clinicopathologic and histopathologic features.
• Comparison of morphologic and phenotypic characteristics.

Main Results:

• PNLH is a reactive process, distinct from neoplastic conditions.
• Distinctive morphologic and phenotypic features aid in differentiating PNLH.
• Accurate diagnosis is achievable in most cases by recognizing these features.

Conclusions:

• Understanding the unique features of PNLH is crucial for accurate diagnosis.
• Distinguishing PNLH from lymphoma and IgG4-related disease is clinically important.
• This review provides guidance for pathologists and clinicians managing PNLH.