Schwannoma : Ancient Change
Deep-seated schwannomas (mediastinum or retroperitoneum) of long standing may show several degenerative changes. They include degenerative-type cytologic atypia (irregularly enlarged multilobed hyperchromatic nuclei, intranuclear vacuoles), cystic change, calcification, hemorrhage, and dense hyalinization. The hyalinized stroma frequently contains hemosiderin-laden macrophages and inflammatory cells. Despite the cytologic atypia, mitotic activity is not increased. These changes have no prognostic significance. This image of an "ancient schwannoma" from retroperitoneum shows cystic change (lower right), dystrophic calcification (left) and hemorrhage (top).