[Osseous lithiasis: an unusual condition]

Bone lithiasis is an uncommon disease unfrequent reported in the literature. Its origin is supported on urothelium and conjuctive tissue bone metaplasia. High suspicious index is needed to establish its diagnosis; where radiological signs and extracorporeal lithotripsy resistence drive to these uncommon entity. Definitive diagnosis is based on histological exam. We report a 49-year-old patient with left obstructive uropathy due to a high ureteral lumbar lithiasis who precised ureterolithectomy and partial ureterectomy after extracorporeal litotripsy failure. Histological exam confirmed bone lithiasis and squamous metaplasia. Epidemiologic, diagnostic and therapeutic aspects are briefly reviewed in literature. Bone calculus treatment includes lithectomy and urothelium resection to avoid posterior recurrence. Possible association to tumoral transformation suggests close evolutive follow-up.