Relapsed IgA Multiple Myeloma as Testicular Plasmacytoma after Quadrable Novel Therapy and Autologous Stem Cell Transplant: A Rare Case Report and Literature Review.

Multiple myeloma (MM) is a clonal neoplasm of plasma cells that may manifest as an extramedullary disease in rare cases. In this case report, we present the rare occurrence of testicular relapse in a 39-year-old patient with IgA MM after 3 years of remission. We discuss the clinical course and management of this unusual presentation and provide a comprehensive literature review of testicular involvement by MM. Despite advances in MM treatment, relapse remains common, highlighting the importance of careful follow-up and timely detection of disease recurrence at atypical sites. This case highlights the need for further research to standardize the diagnosis and treatment of testicular MM.