title: Hemophagocytic lymphohistiocytosis mimicking surgical symptoms and complications: lessons learned from four cases.
abstract: OBJECTIVE
  Hemophagocytic lymphohistiocytosis (HLH) is a severe immunological disorder that leads to a massive inflammatory reaction that may prove rapidly fatal. We show that HLH may present by masquerading as surgical disease or as a postoperative complication leading to delays in diagnosis and treatment.
  
  
  METHODS
  A case series of four children with acute surgical presentation and prolonged unexplained postoperative sepsis, who were diagnosed with HLH.
  
  
  RESULTS
  Four children with different clinical presentations (1. neonatal abdominal distension, 2. ileostomy closure and Hirschsprung's disease, 3. iatrogenic sigmoid perforation and Crohn's disease, and 4. streptococcal toxic shock syndrome with primary peritonitis) were diagnosed with HLH at our regional pediatric surgical centre in the last two years. All developed signs of prolonged postoperative sepsis with hepatosplenomegaly and pancytopenia, requiring intensive care support. In the absence of explanation for their symptoms and deteriorating clinical condition, a total of six 'negative' exploratory laparotomies were performed. Eventually, HLH was diagnosed with bone marrow aspiration after an average of 23 days (range 17-40), following the finding of significantly elevated ferritin (up to 293150 ng/ml) and triglyceride levels. All children improved with initiation of high-dose steroid treatment followed by etoposide and cyclosporin.
  
  
  CONCLUSIONS
  HLH may rarely present with symptoms and signs of surgical disease or complicate post-operative recovery. This diagnosis should be considered in children with unexplained prolonged fever, hepatosplenomegaly and pancytopenia, especially if associated with high ferritin levels. HLH can prove rapidly fatal without appropriate treatment.
authors.affiliation: Alder Hey Royal Liverpool Children's Hospital. siminas1@gmail.com
authors.forename: Sotirios
authors.initials: S
authors.lastname: Siminas
authors.forename: Mark
authors.initials: M
authors.lastname: Caswell
authors.forename: Simon E
authors.initials: SE
authors.lastname: Kenny
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D051359:Lymphohistiocytosis, Hemophagocytic / Q000175:diagnosis*; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis*; D018805:Sepsis / Q000175:diagnosis
keywords: ALT; AST; Alanine aminotransferase; Aspartate aminotransferase; C-reactive protein; CRP; Critical care; HLH; Hemophagocytic lymphohistiocytosis; MRI; Magnetic resonance imaging; NK-cells; Natural killer cells; RSV; Respiratory syncytial virus; SLE; Systemic lupus erythematosus; TNF; Tumour necrosis factor; VAC; Vacuum assisted closure