Histopathology of Relapsing Polychondritis
The histopathology of involved cartilage, regardless of location, is similar and highly characteristic.
The cartilage matrix, which is normally basophilic (blue), becomes acidophilic (pink) when examined by routine hematoxylin and eosin staining. Inflammatory cell infiltrates (initially polymorphonuclear cells and later lymphocytes and plasma cells) invade the cartilage from the periphery inward.
Granulation tissue and fibrosis develop adjacent to inflammatory infiltrates, occasionally resulting in sequestration of cartilage segments. Increased lipids and lysosomes in chondrocytes are demonstrated by electron microscopy. Immunofluorescence may demonstrate immunoglobulin and complement components in the tissue.
