title: Crystalloid podocytopathy with focal segmental glomerulosclerosis in PCM: a case report.
abstract: BACKGROUND
  Crystalloid podocytopathy with focal segmental glomerulosclerosis in plasma cell myeloma (PCM) is rare.
  
  
  METHODS
  We present a case of crystalline deposition in the bone marrow (BM) and various renal cells with only proteinuria as a symptom. As workup for proteinuria, a renal biopsy sample was obtained. EM showed multiple crystalline depositions in renal tubular cells and podocytes. Focal segmental glomerulosclerosis with crystalloid podocytopathy was diagnosed. Because monoclonal gammopathy was detected in the serum and urine, a BM study was also performed. Plasma cells with needle-shaped inclusion bodies were observed. The crystalline deposits in the plasma cells and podocytes were positive for Masson's trichrome and kappa light-chain staining. These findings indicated that the crystalline deposits originated from paraprotein. The case showed a rare process of focal segmental glomerulosclerosis via crystalline deposition in podocytes in plasma cell myeloma.
  
  
  CONCLUSIONS
  Crystalloid podocytopathy is a likely cause of renal damage such as FSGS in PCM, although it is an uncommon mechanism for myeloma kidney.
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, 892, Dongnam-ro, Gangdong-gu, Seoul, 134-727, Republic of Korea. jyl2658@hanmail.net.
authors.forename: You La
authors.initials: YL
authors.lastname: Jeon
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, 892, Dongnam-ro, Gangdong-gu, Seoul, 134-727, Republic of Korea. wileemd@khu.ac.kr.
authors.forename: Woo In
authors.initials: WI
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, 892, Dongnam-ro, Gangdong-gu, Seoul, 134-727, Republic of Korea. eugenius1005@naver.com.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, 892, Dongnam-ro, Gangdong-gu, Seoul, 134-727, Republic of Korea. sykangmd@hanmail.net.
authors.forename: So Young
authors.initials: SY
authors.lastname: Kang
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, 892, Dongnam-ro, Gangdong-gu, Seoul, 134-727, Republic of Korea. meikim96@hanmail.net.
authors.forename: Myeong Hee
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Pathology, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea. sungjig@khnmc.or.kr.
authors.forename: Sung-Jig
authors.initials: SJ
authors.lastname: Lim
authors.affiliation: Division of Nephrology, Department of Internal Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea. ishnephro@khnmc.or.kr.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Lee
mesh_terms: D001853:Bone Marrow / Q000473:pathology*; D000077324:Crystalloid Solutions; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007552:Isotonic Solutions / Q000378:metabolism*; D007668:Kidney / Q000473:pathology; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology*; D050199:Podocytes / Q000473:pathology*; D011507:Proteinuria / Q000473:pathology
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions