Hemophagocytic syndrome

Hemophagocytic syndrome, also known as hemophagocytic lymphohistiocytosis, is a rare condition often associated with viral infections.

Clinical

Features:

• Fever.
• Splenomegaly.
• Jaundice.

Involved organs:

• Lymph nodes.
• Liver.
• Spleen.
• Bone marrow.

Classification

Classified by etiology:

1. Primary, i.e. inherited:
   • Etiology: dysfunction of cytotoxic T lymphocytes with macrophage activating cytokines.
   • Autosomal recessive.
   • Two genes identified:
     • FHL1.
     • FHL2.
2. Secondary:
   • Infection, e.g. EBV (most common infectious etiology), HIV.
   • Malignancy.
   • Rheumatologic condition.

Microscopic

Features:

• Macrophages with phagocytosed:
  • Erythrocytes.
  • Leukocytes.
  • Platelets.

Images:

• Hemophagocytic syndrome - cropped - very high mag. (WC).
• Hemophagocytic syndrome - very high mag. (WC).
• HLH (WC).
• Hemophagocytic syndrome - several images (upmc.edu).

See also

• Hematopathology.
• Myospherulosis.