Subglottic Extramedullary Plasmacytoma With Light Chain Multiple Myeloma Masquerading as Adult-Onset Asthma

Extramedullary plasmacytoma (EMP) arises outside the bone marrow and can be associated with multiple myeloma (MM). A 55-year-old gentleman, who presented with dyspnea and expiratory wheeze, was diagnosed and treated for asthma. A subsequent relapse 6 months later prompted an Otolaryngology consult. Preliminary findings showed a benign-looking nodular lesion at the subglottis. Work-up at our institution revealed an Fludeoxyglucose (FDG) avid left subglottic lesion with multiple bone metastases on a Positron Emission Tomography / Computed Tomography (PET/CT). The patient underwent a panendoscopy and laser excision of the subglottic lesion with subglottic jet ventilation. Histology showed an EMP. Further work-up revealed the presence of kappa light chain MM with adverse cytogenetics. Patient was treated systemically with lenalidomide, bortezomib, and dexamethasone for four cycles with rapid improvement in his symptoms. We review the literature about EMP of the subglottis with MM. We present the first case of subglottic laryngeal EMP with MM managed via CO2 laser excision.