Do Not Ignore Those Raccoon Eyes; They May Indicate Lethal AL Amyloidosis.

Light chain (AL) amyloidosis is a lethal form of systemic amyloidosis that arises from the clonal expansion of CD38+ plasma cells. Organ damage occurs when these plasma cells produce misfolded immunoglobulin light chains, which form amyloid fibrils and deposit in tissues. A minority of patients with AL amyloidosis show "raccoon eyes" caused by increased vascular fragility from accumulation of amyloid fibrils. Amyloidosis can be directly associated with bleeding diathesis due to factor X deficiency as factor X binds to amyloid fibrils primarily in the liver and spleen. A 65-year-old Caucasian male presented with random bruising in the upper chest and around the eyes for 1.5 years. Physical examination was unremarkable, except for neck bruising. Pertinent workup showed protein electrophoresis with a faint M spike, increased serum lambda light chains, a kappa to lambda ratio of 0.06, increased Bence-Jones proteins, reduced factor X activity, elevated NT-proBNP. The bone marrow biopsy was positive for Congo red stain for amyloid protein. Magnetic resonance imaging revealed diffuse enhancement of the right and left ventricle subendocardial late gadolinium, consistent with cardiac amyloidosis. The patient started systemic therapy with a regimen of daratumumab, cyclophosphamide, bortezomib, and dexamethasone. After one cycle of therapy, lambda light chains normalized with an improvement in bruising. Diagnostic delays for cardiac patients are concerning as the median survival rate among these patients, when not treated, is approximately 6 months after the onset of symptoms. Since timely treatment can prevent organ damage, clinicians should be aware of specific clinical signs such as raccoon eyes and the importance of systemic evaluation for a prompt diagnosis.