Systemic mastocytosis with an associated hematological neoplasm (SM-AHN) is a rare diagnosis commonly associated with myeloid disorders. Herein, we describe the case of a 53-year-old female diagnosed with systemic mastocytosis (SM) in conjunction with renal light chain amyloidosis (AL) and smoldering myeloma. Although cytokines such as IL-6 may play a role in the proliferation of plasma cells, delays in the diagnosis of SM and paucity of relevant studies cast uncertainty on whether the associated disease is secondary to the mast cells or etiologically independent. To our knowledge, this is the first case of confirmed renal AL disease in conjunction with SM. We review and summarize the available literature describing SM in association with plasma cell disorders.