Giant plasma cells with multiple immature nuclei in a young woman with newly diagnosed multiple myeloma

Background Multiple myeloma with giant multinucleated plasma cells is a very rare entity and mostly reported cases are dated. This plasma cell morphology has been observed after monoclonal antibody treatments, such as daratumumab, and patients have experienced a worse prognosis with partial responses and a high rate of relapse. Results Here, we showed a newly diagnosed multiple myeloma with giant plasma cells with multiple (up to 13) immature nuclei who achieved a complete remission after a first line therapy and underwent to autologous hematopoietic stem cell transplantation, as per international guidelines. A newly diagnosed multiple myeloma with giant plasma cells with multiple (up to 13) with loose chromatin, inconspicuous nucleoli, intense cytoplasmatic basophilia, expanded Golgi apparatus, and membrane blebs mimicking a hairy cell leukemia variant. The patient achieved a complete remission after a first line therapy and underwent to tandem autologous hematopoietic stem cell transplantation.