This is a retrospective chart review of all patients cared for at Monroe Carell Jr. Children's Hospital at Vanderbilt including the following:

• patients between 2007-2009 with malignancy, Langerhans cell histiocytosis (LCH) or hemophagocytic lymphohistiocytosis (HLH) and a central venous catheter who were under 23 years of age at time of diagnosis in order to ascertain the associated symptoms, management and outcome of all episodes of non-neutropenic fever.
• to identify a subset of low-risk patients that can be safely managed without use of empiric antibiotics.

Inclusion Criteria:

• Diagnosed with malignancy, Langerhans cell histiocytosis,or hemophagocytic lymphohistiocytosis from 2007 through 2010
• Under 23 years at time of diagnosis of malignancy, Langerhans cell histiocytosis,or hemophagocytic lymphohistiocytosis
• Treated at Monroe Carell Jr. Children's Hospital at Vanderbilt for aforementioned diagnosis from 2007 through 2012
• While on immunosuppressive therapy with a central venous line in place had at least one documented episode of fever (defined as ≥ 38.0°Celsius orally for over 30 minutes or ≥ 38.3°Celsius orally x1).

Exclusion Criteria:

• Does not meet all inclusion criteria as stated above

All patients diagnosed with and treated for malignancy, Langerhans cell histiocytosis ,or Hemophagocytic lymphohistiocytosis between 2007 through 2010 at Monroe Carrell Jr. Children's Hospital at Vanderbilt under the age of 23 at diagnosis.