Necrobiotic xanthogranuloma

Necrobiotic xanthogranulomas are a rare form of cutaneous non-Langerhans cell histiocytosis.

Epidemiology

The condition occurs mostly in older adults .

Clinical presentation

Patients demonstrate cutaneous papules that develop into large, firm plaques, papules and nodules, which are often yellow . The most common site is the periorbital skin . Involvement of the periorbital soft tissues can cause ptosis, exophthalmos, diplopia, restricted ocular movement and pain .

Pathology

The exact etiology of the condition is unknown due to its rarity .

Associations

Most patients have a monoclonal gammopathy, which has the potential to develop into multiple myeloma or other lymphoproliferative disorders .

Radiographic features

Cross-sectional imaging of the face on CT or MRI demonstrates soft tissue thickening or masses in the periorbital region. Internal organs (e.g. the liver) may also be affected.