Miscellaneous Xanthomas

Miscellaneous Xanthomas
Jonathan B. McHugh, MD
Key Facts
Terminology
  • Mass-forming collection of lipidized macrophages
  • Reactive process usually resulting from altered serum lipid levels
Etiology/Pathogenesis
  • Associated with hereditary lipoproteinemias and occasionally secondary lipoproteinemias
  • May also occur in normolipemic patients
Clinical Issues
  • Usually occur in skin and subcutaneous tissue
  • Occasionally arise in deep soft tissues (tendon, synovium, bone)
  • Classified based on clinical features and gross appearance
  • Excellent prognosis
Microscopic Pathology
  • Specific classification requires clinicopathologic correlation
  • Generally consist of mixtures of foamy and nonfoamy macrophages with secondary changes including inflammation, fibrosis and cholesterol cleft formation
Top Differential Diagnoses
  • Giant cell tumor of tendon sheath
  • Juvenile xanthogranuloma
  • Plexiform xanthoma
  • Lipidized benign fibrous histiocytoma (dermatofibroma)
  • Verruciform xanthoma
Xanthelasmas typically symmetrically involve bilateral upper and lower eyelids and periorbital skin. Sharply demarcated soft yellow papules and plaques with a yellow color are characteristic.
Eruptive xanthomas are characterized by the sudden appearance of crops of small yellow papules with an erythematous base. Eruptive xanthomas typically occur in the buttock, thigh, and shoulder regions.
TERMINOLOGY
Definitions
  • Mass-forming collection of lipidized macrophages
  • Reactive process usually resulting from altered serum lipid levels
ETIOLOGY/PATHOGENESIS
Hereditary or Nonhereditary
  • Associated with hereditary lipoproteinemias and occasionally secondary lipoproteinemias (e.g., diabetes, hypothyroidism, primary biliary cirrhosis)
  • May also occur in normolipemic patients
CLINICAL ISSUES
Presentation
  • Usually occur in skin and subcutaneous tissue
  • Occasionally arise in deep soft tissues (tendon, synovium, bone)
  • Classified based on clinical features
    • Xanthelasma
      • Soft yellow plaques; predilection for eyelids and periorbital skin; often bilateral
    • Eruptive xanthoma
      • Sudden onset of small yellow papules with erythematous halo; predilection for gluteal region, thigh, and shoulders
    • Tuberous xanthoma
      • Firm yellow subcutaneous nodules and plaques; predilection for elbow, knee, gluteal region, and fingers
    • Tendinous xanthoma
      • Soft tissue mass associated with tendons, ligaments, &/or fascia; predilection for hands, feet, and Achilles tendon
      • May impair joint function but often asymptomatic
    • Plane xanthoma
      • Variably sized yellow macules; predilection for palmar creases
      • In normolipemic patients, consider underlying reticuloendothelial malignancy
    • Cerebrotendinous xanthomatosis
      • Rare autosomal recessive disease; sterol 27-hydroxylase gene (CYP27A) mutation
      • Enzyme involved in bile acid synthesis; defect results in accumulation of cholestanol, which is deposited systemically
      • Bilateral Achilles tendon xanthomas and cataracts; CNS symptoms include ataxia, dementia, dysarthria, psychiatric disturbances, and seizures
Treatment
  • May regress with medical therapy for hyperlipidemia or underlying cause if secondary
  • Conservative excision can be employed for large or symptomatic lesions
Prognosis
  • Excellent prognosis; surgically treated lesions may recur
MACROSCOPIC FEATURES
General Features
  • Diffuse or circumscribed with variegated yellow, tan, and white appearance
Size
  • Generally a few millimeters to centimeters depending on type
  • Tendinous xanthomas can be quite large (up to 20 cm)
MICROSCOPIC PATHOLOGY
Histologic Features
  • Specific classification requires clinicopathologic correlation
  • Consist of mixtures of foamy and nonfoamy macrophages with variable inflammation, fibrosis, and cholesterol cleft formation
  • Xanthelasmas and plane xanthomas consist of sheets of foamy macrophages
  • Eruptive xanthomas consist mostly of nonfoamy macrophages with some foamy macrophages
  • Tuberous and tendinous xanthomas consist of sheets of foamy macrophages with chronic inflammation, fibrosis, and cholesterol clefts with giant cells
DIFFERENTIAL DIAGNOSIS
Tags:
Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Miscellaneous Xanthomas

Full access? Get Clinical Tree
Get Clinical Tree app for offline access