title: Liesegang rings in xanthogranulomatous pyelonephritis: a case report.
abstract: Liesegang rings are concentric noncellular lamellar structures, rarely seen in vivo, occurring as a consequence of the accumulation of insoluble products in a colloidal matrix. These characteristic structures are a rare phenomenon usually found in association with cystic or inflammatory lesions and may be mistaken for parasites. The authors examined Liesegang rings from an inflammatory kidney lesion identified previously as a tumoral lesion on computerized tomography. On microscopic evaluation, Liesegang rings can be mistaken for eggs and larvae of parasites, psammoma bodies and calcification. Special stains like PAS, Grocott, von Kossa and Masson's trichrome facilitate the diagnosis.
authors.affiliation: Hospital de Clínicas de Porto Alegre, RS, Brazil.
authors.forename: Karla Laís
authors.initials: KL
authors.lastname: Pegas
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Edelweiss
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cambruzzi
authors.forename: Cláudio Galleano
authors.initials: CG
authors.lastname: Zettler