Plasmacytomas can be classified as osseous (medullary) or non-osseous (extramedullary). Extramedullary plasmacytomas (EMP) are uncommon and may be primary or associated with multiple myeloma (MM). EMP arising from the mediastinum is extremely rare. We report two patients who presented with symptomatic mediastinal masses. On evaluation, these turned out to be EMP with coexisting MM.These two cases are being presented for their rarity and to highlight the unusual presentations of MM.