Oxalosis in a Patient with Livedo Reticularis

A 27-year-old man with terminal renal failure requiring peritoneal dialysis for the past 2 years was referred to the dermatologist for evaluation of red violaceous macular skin lesions consistent with livedo reticularis. These lesions had appeared suddenly on his legs (Figure 1). He had first experienced recurrent nephrolithiasis at the age of 14. Results from urine analysis and abdominal ultrasound revealed chronic kidney failure. Because the patient had a sister with similar findings, primary hyperoxaluria (PH) was suspected and genetic testing was performed in all members of his family. The results confirmed PH type 1 (PH1) in both our patient and his sister, who had died 8 years after the establishment of the diagnosis. A biopsy of the livedo reticularis lesions revealed deposits of a yellowish brown crystalline material within the lumen and the media of medium vessels in the hypodermis associated with a histiocytic giant cell reaction (Figure 2a). There was no evidence of extravascular calcium deposition in the sections examined. The deposits were intensely birefringent under polarized light, and classic speculated crystals of oxalate salts were observed (Figure 2b). No focal epidermal or superficial dermal necrosis was seen. On the basis of the histopathologic findings, the diagnosis of oxalate crystal-induced vascular disease was established. The patient subsequently developed complications including pancreatitis and peritonitis. He underwent hemodialysis until a combined liver-kidney transplant could be performed.