Widespread crystalline inclusions affecting podocytes, tubular cells and interstitial histiocytes in the myeloma kidney

Light Chain Proximal Tubulopathy: Expanding the Pathologic Spectrum with and without Deposition of Crystalline Inclusions

“…The crystals are electron dense usually rhomboid, square, or rectangular in configuration and found in the lysosomes of PT cells by EM. Rarely, crystals can be seen in glomerular cells including podocytes and as well as in interstitial cells and histiocytes in the kidney [9][10][11][12][13][14][15]. Our case series with 3 kappa and 6 lambda-type LCPT is adding more information to existing literature with light, IF and EM findings.…”

“…The LCPT is a unique entity in which the LC crystals of mostly kappa type are deposited in the cytoplasm of the PT cells and detected as intracytoplasmic droplets by LM and IF and electron dense crystals of a variety of shapes by EM in majority of cases [19][20][21][22][23][24][25]. Although crystals accumulate predominantly in PT cells, rare case reports described the presence of crystals in the glomeruli and interstitial cells [9][10][11][12][13][14]24]. Glomerular crystals may be detected by LM, IF and EM in podocytes, mesangial, endothelial and parietal cells [6,9,[11][12][13][14]24].…”

“…Although crystals accumulate predominantly in PT cells, rare case reports described the presence of crystals in the glomeruli and interstitial cells [9][10][11][12][13][14]24]. Glomerular crystals may be detected by LM, IF and EM in podocytes, mesangial, endothelial and parietal cells [6,9,[11][12][13][14]24]. Interstitial cells and histiocytes in the interstitium may contain crystals and they can be detected by LM, IF, and EM [10,12,14,24].…”

Renal Light Chain Deposition Associated with the Formation of Intracellular Crystalline Inclusion Bodies in Podocytes: A Rare Case Report

“…In this previous study, the diagnosis of malignant plasma cells could not be established for some patients at the time of renal biopsy, although the patients were diagnosed later in a follow-up study with the gradual emergence of corresponding clinical manifestations (10). In contrast, it is very rare to present large quantities of crystalline inclu- sions deposited in podocytes and only 10 cases have been reported to date (2,5,6,(11)(12)(13)(14)(15)(16)(17) (Table). Therefore, the present case, which was identified via electron microscopy, represents the 11th case reported.…”

Ultrastructural Study of Electron Dense Deposits in Renal Tubular Basement Membrane: Prevalence and Relationship to Epithelial Atrophy

“…Crystalline deposits were found in tubules as intracellular elongated crystals in lysosomes, intracellular rhomboid masses in phagolysosomes, extracellular crystals in the tubular lumen, and as linear deposits external to the TBMs. Crystalline cytoplasmic inclusions showing rhomboid and oval shapes have been described previously in myeloma by us and others [6,7] and the content of light chain fragments confirmed by immunoelectron microscopy [1]. …”