RESUMO
Chronic renal failure can give rise to a wide spectrum of oral manifestations, owing mainly to secondary hyperparathyroidism complicating this disease. However, any systemic disease responsible for kidney failure can produce oral manifestations, which can be misdiagnosed. This report describes the case of a 40-year-old male patient referred for oral assessment before kidney and liver transplantation. He had primary hyperoxaluria complicated by end-stage renal failure and secondary hyperparathyroidism. Panoramic radiography indicated not only external root resorption, but also maxillary and mandibular radiolucencies consistent with brown tumors. Unexpectedly, histologic study of the bone biopsy specimen led to the diagnosis of jaws oxalosis. Primary hyperoxaluria is a systemic genetic disease. The affected genes are involved in glyoxylate metabolism and their deficiency results in overproduction of oxalates. Inability of the kidney to excrete oxalates leads to deposition of these crystals in almost all tissues (oxalosis) and to multiple-organ failure. Several oral findings have been described in patients with oxalosis, such as periodontal disease and root resorptions, but radiolucencies in the jaws have rarely been described. This case report is of particular interest because of the unusual location of oxalate crystal deposition in the jaws, which could be misdiagnosed in a patient with renal failure and secondary hyperparathyroidism.