Focal xanthogranulomatous pyelonephritis with associated bone metaplasia

Focal xanthogranulomatous pyelonephritis of the left lower pole was acciden tally discovered in a 34-year-old woman at sonography, The patient had no h istory of stones and urinary tract infection and both conventional radiolog y and CT scan revealed radiated calcifications within a well-circumscribed mass, Surgical treatment consisted of enucleoresection of the lesion, and h istopathology revealed a nucleus of bone metaplasia, To the best of our kno wledge, metaplastic bone formation has never been documented before with xa nthogranulomatous pyelonephritis, Copyright (C) 2000 S. Karger AG, Basel.