Figure 4. Crystal-storing Histiocytosis. Patient with Essential Monoclonal Gammopathy (IgA-kappa Type). Marrow Biopsy Treated with Giemsa Stain.

(A) The marrow shows a diffuse infiltrate of histiocytes (larger cells) with crystalloid cytoplasmic inclusions (original magnification ×1,600). (B) Plasma cells were infrequent. In this field two are shown by horizontal arrows. Three histiocytes with cytoplasmic crystals are indicated by the vertical arrows (original magnification ×4,000). (Used from reference ³² with permission of the American Society of Hematology.)