Collagenofibrotic glomerulopathy- report of a rare renal disease with serial biopsies.

Collagenofibrotic glomerulopathy or collagen type-III glomerulopathy is a rare glomerular disease characterised by the deposition of type III collagen fibres in the subendothelial space and mesangium of the glomerulus. Here, we present a case of collagenofibrotic glomerulopathy in a 49-year-old Indian female, the first to be reported from Singapore. Renal biopsy showed PAS (periodic acid-Schiff), silver and Congo red negative, amorphous extracellular material that expanded mesangial and subendothelial regions. Such materials were strongly positive for anti-collagen III immunofluorescent staining. Under electron microscopy, the mesangial and some subendothelial regions were greatly expanded by abundant collagen fibres which were different from normal collagen III fibres in both appearance and periodicity. The availability of past renal biopsies for reference offered insight into disease progression. From the initial diagnosis of focal segmental glomerulosclerosis to eventually collagenofibrotic glomerulopathy over a time span of more than 10 years, this case highlights the gradual accumulation of collagen fibres in the glomeruli before classical features are apparent. It also emphasises the importance of electron microscopy in the diagnosis of this disease.