PMC9868391_01
Histology and time course for Case 1. (A) Light microscopy of the external iliac lymph node exhibiting follicular hyperplasia (left lower) and infiltration by CD138+ plasma cells. (B,C) Renal biopsy. (B) Light micrograph showing diffuse mesangial and endocapillary hypercellularity. (C) Electron micrograph showing subendothelial widening with neo-densa (left, silver impregnation) and glomerular basement membrane thickening (right). Arrows indicate argyrophilic neo-densa. Scale bar, 2.5 mum. PAS: Periodic acid-Schiff. PAM: Periodic acid methenamine. (D) Clinical time course of Case 1. Hb, hemoglobin, Cre, creatine, Up, urinary protein.
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F1
She underwent a lymph node biopsy in the right external iliac region and was diagnosed with iMCD (Figure 1A). The remaining glomeruli showed diffuse mesangial hypercellularity, with focal endocapillary hypercellularity (Figure 1B). Electron microscopy demonstrated subendothelial widening with neo-densa and thickening of the glomerular basement membrane partly due to diabetes (Figure 1C). Two months later, her serum creatinine and 24-h urinary protein levels had declined to 1.54 mg/dl and 1.6 g/day, respectively (Figure 1D).
PMC9868391_02
Histology and time course for Case 2. (A) Light micrograph of the lymph node showing follicular hyperplasia (left lower) and infiltration by plasma cells which are positive for CD 138. (B-E) Renal biopsy. (B) Light micrograph showing focal endo- and extra-capillary hypercellularity with hyaline deposits (arrows). (C) Tubular injury with red blood cell casts is observed. (D) Immunofluorescence micrograph showing granular mesangial and capillary staining for IgG, IgA, IgM, C1q, and C3. (E) Electron micrograph showing mesangial deposits (arrows). PAS: Periodic acid-Schiff. PAM: Periodic acid methenamine. (F) Clinical time course of Case 2. Hb, hemoglobin; Cre, creatine; Up, urinary protein.
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F2
A biopsy of the right axilla revealed plasma cell infiltration, leading to a diagnosis of iMCD (Figure 2A). Renal biopsy revealed focal endo- and extra-capillary hypercellularity with hyaline deposits (Figure 2B). Tubular injury with red blood cell casts was also observed (Figure 2C). Immunofluorescence microscopy revealed 1 + to 2 + granular mesangial and capillary staining for IgG, IgA, IgM, C1q, and C3, corresponding to hyaline deposits (Figure 2D). Although large hyaline deposits were not observed by electron microscopy, small mesangial deposits were identified (Figure 2E). The patient remained in remission (Figure 2F).
PMC9868391_03
Histology and time course for Case 3. (A) Light micrograph of the lymph node showing follicular hyperplasia (left lower) and infiltration by plasma cells which are positive for CD 138. (B,C) First renal biopsy. (B) Light micrograph showing slight mesangial expansion and focal segmental glomerular sclerosis. (C) Electron micrograph showing focal subepithelial deposits (arrows). (D,E) Second renal biopsy. (D) Light micrograph showing focal global and segmental sclerosis with diffuse glomerular basement membrane lucencies (red arrows). (E) Electron micrograph showing subepithelial and intramembranous deposits (red arrows). Some of the intramembranous deposits are electron-lucent and granular appearance (yellow arrows). PAS: Periodic acid-Schiff. PAM: Periodic acid methenamine. (F) Clinical time course of Case 3. Hb, hemoglobin; Cre, creatine; Up, urinary protein; RRT, renal replacement therapy.
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F3
At the age of 44 years, he presented with multiple enlarged lymph nodes, and a left axillary biopsy revealed iMCD (Figure 3A). Renal biopsy revealed a slight mesangial expansion and focal segmental glomerular sclerosis with podocyte hyperplasia (Figure 3B). Electron microscopy revealed only a few subepithelial deposits, which suggested atypical membranous glomerulonephritis (Figure 3C). Light microscopy revealed focal global and segmental sclerosis with diffuse glomerular basement membrane lucency on sliver staining (Figure 3D). Electron microscopy revealed the presence of subepithelial and intramembranous deposits (Figure 3E). His renal function further diminished, and he required renal replacement therapy (Figure 3F).