What type of substance is hemosiderin in histological sections?

Hemosiderin is classified as a pigment, which is significant in histopathology for its role in iron storage and its visual identification in tissue sections. It is a brownish-yellow granule that appears within cells, particularly in conditions when there is excess iron, such as hemochromatosis or chronic hemolytic anemia. In tissue sections stained with special techniques such as Prussian blue, hemosiderin can be readily visualized. This characteristic is crucial for pathologists since the accumulation of hemosiderin can indicate underlying pathologies related to iron metabolism and storage. Identifying and understanding hemosiderin's presence helps in diagnosing various diseases associated with iron overload.