The bone marrow examination of a 52-year-old man with osseous lytic lesions and an IgG kappa monoclone is shown. Image description: (A) Bone marrow aspirate, Bone marrow biopsy sections with immunohistochemistry staining for CD79a (B) and CD56 (C) Source: The Lancet *This case is from Docplexus editorial team for educative purpose only