title: [A case of non-secretory myeloma with crystal-storing histiocytosis].
abstract: Crystal-storing histiocytosis (CSH) is a rare event observed in association with lymphoproliferative diseases, and mainly occur in plasma cell dyscrasias. It is presumed to be an intra-lysosomal accumulation of the secreted paraproteins. Crystal formation can be seen inside histiocyte-like cells with phagocytosed crystalline inclusions in the bone marrow and extramedullary sites. CSH is a rare morphological entity with poor prognostic implications and may be confused with Gaucher or pseudo-Gaucher cells. Herein we report a case of non-secretory myeloma associated with CSH showing a poor clinical course. A 79-yr-old male presenting with dizziness was evaluated in hematology department for anemia. Laboratory tests revealed Hb of 4.9 g/dL and β2-microglobulin of 21,000 ng/mL (reference range, 0-370). Presence of monoclonal protein was not detected on protein electrophoresis and immunofixation in serum and urine. However, serum free light chain assay showed an increased kappa-light chain level of 126 mg/L (reference range, 3.3-19.4) resulting in an increased kappa/lambda ratio. The bone marrow touch print showed numerous plasma cells and crystal-laden histiocytes and immunohistochemical stainings on bone marrow biopsy revealed positivity for CD38, CD56 and kappa in the plasma cells and CD68 and kappa in crystal-laden histiocytes.
authors.affiliation: Department of Laboratory Medicine, Gachon University Gil Hospital, Incheon, Korea.
authors.forename: Soon-Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Jeong-Yeal
authors.initials: JY
authors.lastname: Ahn
authors.forename: Yiel-Hea
authors.initials: YH
authors.lastname: Seo
authors.forename: Pil-Hwan
authors.initials: PH
authors.lastname: Park
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Kim
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Song
authors.forename: Ji-Hun
authors.initials: JH
authors.lastname: Jeong
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001854:Bone Marrow Cells / Q000473:pathology; D015614:Histiocytosis / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D008297:Male; D009101:Multiple Myeloma / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D000097382:CD68 Molecule
chemical_list: D051997:ADP-ribosyl Cyclase 1; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D007145:Immunoglobulin kappa-Chains; C067980:CD68 antigen, human; D000097382:CD68 Molecule