Multiple myeloma revealed by laryngeal dyspnea: A case report

Background: Extramedullary plasmacytoma is a rare plasma cell neoplasm, representing less than 4% of all plasma cell disorders, with a predilection for the head and neck region. While Extramedullary plasmacytoma typically has a favorable prognosis with localized treatment, approximately one-third of cases progress to multiple myeloma within two years. 
Case Presentation: We report the case of a 50-year-old male presenting with acute laryngeal dyspnea due to a locally advanced laryngeal mass. Emergency tracheotomy was performed to secure the airway. Clinical evaluation and imaging revealed a pan-laryngeal tumor with cartilage destruction and extra-laryngeal extension. histopathological and immunohistochemical analysis confirmed the diagnosis of extramedullary plasmacytoma with KAPPA light chain restriction. Further investigations identified diffuse osteolytic lesions and 15% plasma cell infiltration in the bone marrow, leading to the diagnosis of multiple myeloma. The patient received chemotherapy (bortezomib, thalidomide, and dexamethasone) followed by autologous stem cell transplantation. He showed a favorable clinical and biological response, allowing for successful tracheostomy closure and continued maintenance therapy. 
Conclusion: This case highlights the diagnostic challenges of laryngeal plasmacytoma and the importance of considering EMP in patients with submucosal laryngeal masses. Given the potential for progression to MM, long-term monitoring and a comprehensive treatment approach remain essential for optimizing prognosis.