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Here we present a bone marrow smear from a patient with monoclonal gammopathy of uncertain significance (MGUS). Among the cells found, plasma cells may sporadically be found that have numerous and large intracytoplasmic vacuoles, referred to as Russell's bodies, which represent the immunoglobulins retained. Such cells are known as Mott cells. They are pathognomonic of sleeping sickness (African trypanosomiasis) found in the brain in the late stage and can be seen in reactive plasmacytosis, autoimmune-mediated diseases, and conditions like Wiskott-Aldrich syndrome and neurofibromatosis.