Conclusion

This case report describes the challenging diagnosis of a non-secretor plasmablastic plasma cell myeloma and highlights the importance of remaining vigilant during morphological evaluation, regardless of the initially suggested diagnosis. Furthermore, it stresses how essential it is to integrate clinical, radiological and laboratory findings to obtain all necessary information for a correct diagnosis, especially with challenging and rare entities. Although there are no comprehensive criteria to discriminate plasmablastic lymphoma from plasmablastic non-secretor myeloma, distinction is important, as the treatment for these two diseases is different.