Extramedullary plasmacytoma associated with angiofollicular lymph node hyperplasia

Area of Science:

• Pulmonology
• Oncology
• Pathology

Background:

• Angiofollicular lymph node hyperplasia (ALNH) is a rare benign condition.
• Extramedullary plasmacytoma (EMP) is a plasma cell tumor outside the bone marrow.

Observation:

• A case of hyaline-vascular type ALNH involving pulmonary lymph nodes and lung is presented.
• The lesion caused left lower lobe main bronchus obstruction due to an associated EMP.
• Immunoperoxidase staining showed a monoclonal IgG-lambda pattern in the tumor cells.

Findings:

• The EMP exhibited a monoclonal plasma cell population.
• The surrounding ALNH showed a polyclonal plasma cell population.
• This contrast suggests a neoplastic transformation within the ALNH.

Implications:

• This case demonstrates the neoplastic potential of angiofollicular lymph node hyperplasia.
• It underscores the importance of thorough pathological evaluation for ALNH.
• Further research into the pathogenesis of ALNH transformation is warranted.