Abstract
BACKGROUND: Raccoon eyes or periorbital ecchymosis is caused by blood tracking into periorbital tissues, which is mostly recognized in injuries of head and neck, basal skull fractures, convexity fractures and facial fractures. It was also reported in systematic disorders, such as multiple myeloma, amyloidosis, Kaposi's sarcoma, migraine and neuroblastoma. However, it is unusual to see a patient showing periorbital purpura after kidney biopsy with no other ecchymosis. Here, we firstly reported this rare symptom after kidney biopsy in a patient who was finally diagnosed as immunoglobulin light chain (AL) amyloidosis. CASE PRESENTATION: A 64-year old woman was admitted to our clinic with 1.5 years history of sub-nephrotic proteinuria and slowly progressive deterioration of renal function. Laboratory -investigations revealed an M-peak in the λ fraction of IgA and concentrations of serum free-light-chain (FLC) were 44.95 mg/L for κ isotype and 173 mg/L for λ isotype. Unexpectedly the patient showed periorbital purpura 24 h later after kidney biopsy with no more other ecchymosis. Renal biopsy showed massively glomerulosclerosis, interstitial fibrosis with positively Congo red staining in mesangial areas. For fluorescent staining, the kidney tissue showed strongly λ light-chain deposition. The fibrils (8-12 nm in diameter) were confirmed by electron micrograph. CONCLUSIONS: This case firstly reported this rare symptom after the kidney biopsy in a patient who was finally diagnosed as AL amyloidosis. And this unique sign of periorbital ecchymosis warrants more attention as an early cue of amyloidosis.