[Multiple extramedullary plasmacytomas from the whole respiratory system]

Area of Science:

• Oncology
• Pathology

Background:

• Extramedullary plasmacytoma (EMP) is a plasma cell neoplasm arising outside of the bone marrow.
• While typically found in the upper respiratory tract, pulmonary involvement is exceptionally rare.

Observation:

• A 50-year-old male presented with bilateral hilar masses on chest radiography.
• Open lung biopsy confirmed pulmonary plasmacytoma; nasal biopsies also showed plasma cell tumors.
• Bronchoscopy revealed extensive, hemorrhagic tumorous lesions in both main-stem bronchi.

Findings:

• The patient exhibited an IgA (kappa) M-component in serum and kappa Bence Jones proteins in urine.
• This case represents the first documented instance of widespread multiple EMPs localized to a single organ system (respiratory tract).
• The clinical course suggests localized bone involvement rather than aggressive multiple myeloma.

Implications:

• This unique presentation expands the understanding of EMP localization and behavior.
• The etiology may involve endobronchial metastasis or a multicentric autochthonous process.
• Further research is warranted to elucidate the pathogenesis of respiratory-system-confined EMPs.