leukocytoklastisk

Leukocytoklastisk, often written leukocytoclastic in English, is a histopathological term describing the fragmentation of neutrophil nuclei (karyorrhexis) and the release of nuclear debris in tissue during inflammation. It is not a disease, but a microscopic feature that can accompany certain inflammatory processes, especially small vessel vasculitis.

In tissue samples, leukocytoklasis appears as fragmented neutrophil nuclear material scattered around small blood vessels, often with accompanying fibrinoid necrosis of the vessel walls and a perivascular inflammatory infiltrate. Immunofluorescence or immunohistochemistry may reveal immune complex deposition or complement activation, depending on the underlying process.

Leukocytoklasis is most commonly associated with leukocytoclastic vasculitis, a term used for small-vessel vasculitis that can be idiopathic or secondary to infections, drugs, or systemic diseases. Conditions in which leukocytoklasis may be observed include hypersensitivity vasculitis, IgA vasculitis (Henoch-Schönlein purpura), cryoglobulinemic vasculitis, and other immune complex–mediated vasculitides. Clinically, such vasculitis often presents with palpable purpura, typically on the lower extremities, and may involve systemic symptoms depending on organ involvement.

Diagnosis relies on a combination of clinical presentation and histopathology from a biopsy, usually of affected skin. Leukocytoklastisk is a valuable descriptive feature that supports a small vessel inflammatory process but is not specific to a single disease; clinical correlation and additional laboratory testing are essential for an accurate diagnosis.