Plasma cell dyscrasia is a spectrum of diseases characterized by monoclonal proliferation of plasma cells, secreting one type of Ig-antibody (heavy or light chain). Best known in this spectrum is multiple myeloma, although the most common is MGUS (monoclonal gammopathy of undetermined significance). Many lesions in the spectrum can actually evolve to multiple myeloma.

Extramedullary plasmacytomas are rare and usually affect the head and neck region, mainly in the upper aerodigestive tract. Involvement of the stomach as in this case, is more rare.