Clinical image description

A 54-year-old man was admitted to the hematology department for exploration of splenomegaly. The blood count showed an isolated normochromic normocytic anemia (9.9 g/dL). Bone marrow aspiration showed a rich marrow with an estimated 35% plasma cell infiltration made up of dystrophic plasma cells (plasma cells with flamed cytoplasm, centered nuclei, multinuclearity), making the diagnosis of multiple myeloma. However, associated with this plasma cell infiltration, the marrow was infiltrated by abnormal histiocytes (Figure 1): Large foamy cells, filled with numerous small vacuoles and navy bluehistiocytes with dense and coarsely granular cytoplasm, raising the suspicion of a Niemann-Pick disease.

Figure 1: Medullary smear stained by May Grunwald Giemsa, seen at magnification (x 40(a); x100 (b,c,d)), showing the presence of seableu histiocytes and dystrophic plasma cells.

References

1. Portier E, Talbot A, Nguyen Y, et al. Multiple myeloma occurring in a case of Niemann-Pick disease Type B: A pathophysiological link?. Br J Haematol. 2022; 197: e53-e55.