Table 1

Fever

Splenomegaly

Hepatomegaly

Lymphadenopathies

Rash

CNS symptoms (seizures, confusion etc...)

Abdominal pain, distention

Laboratory abnormalities

Anemia

Thrombocytopenia

Neutropenia

Hypertriglyceridemia

Hypofibrinogenemia

Hyperbilirubinemia

DIC and increased d-dimers

Pathology findings

Needle aspirate or biopsy of bone marrow, liver, spleen, lymph node:

   • Organ infiltration by activated T cells mostly of the CD8 lineage (CD25 and HLA class II expression) and macrophages)

Serial aspirate(s)/biopsy(ies) may be needed to ascertain HS

   • Hemophagocytosis

   • Indication of potential trigger (infection, malignancy...)

Lumbar puncture:

   Pleiocytosis with activated T cells and/or macrophages

   Hemophagocytosis

May be positive even in the absence of clinical CNS involvement