Cytophagic histiocytic panniculitis

Definition

This is a specific tissue reaction pattern, in which haemophagocytosis is thought to be stimulated by lymphokines released by T-cells. It is seen in association with a variety of conditions;

• lymphoproliferative disorders

  • subcutaneous panniculitis-like T-cell lymphoma

  • NK/T-cell lymphomas

• allogeneic bone marrow transplantation

• various infections

• hypersensitivity to mosquito bites

• lipid-rich intravenous infusion

• connective tissue disease

Clinical features

There are recurrent violaceous, often purpuric and ulcerated subcutaneous nodules, typically over the extremities, accompanied by pyrexia, generalised lymphadenopathy, hepatosplenomegaly with liver disfunction, serous effusions, pancytopenia an coagulopathy.

Histopathology

Subcutaneous fat lobules are infiltrated by macrophages and lymphocytes with scattered "beanbag" cell (,macrophages with ingested erythrocytes, lymphocytes and platelets).

Immunohistochemistry

The histiocytes are CD68-positive and negative for T-cell markers.

References

Liu, V. and McKee, P.H. Cutaneous T-cell lymphoproliferative disorders: approach for the surgical pathologist: recent advances and clarification of confused issues. Adv Anat Pathol 2002;9:79-100.

This page last revised 27.12.2002.

©SMUHT/PW Bishop