title: Deep-seated congenital juvenile xanthogranuloma: report of a case with emphasis on cytologic features.
abstract: BACKGROUND
  Juvenile xanthogranuloma (JXG) is a rare, benign non-Langerhans cell histiocytosis that usually occurs in the head, neck or upper trunk of neonates and young children. Lesions appear most frequently as solitary cutaneous nodule, but in 12% of cases they are multiple and in 5%, subcutaneous or deep-seated. In 4% of cases they are systemic. Histopathologically, deep lesions tend to be more cellular and monotonous, with fewer Touton cells. Independent of its location, the prognosis is excellent, even after incomplete resection. The lesions usually resolve spontaneously within 3 years of diagnosis.
  
  
  METHODS
  A child was born with a large, deep-seated cervical mass that was initially evaluated by fine needle aspiration biopsy, which disclosed vague, granulomatous aggregates with monotonous, histiocytic CD68-positive cells. The surgical specimen histology revealed a JXG with skeletal muscle invasion. Complete reexcision was performed 2 months later after regrowth of the tumor.
  
  
  CONCLUSIONS
  Deep-seated neonatal JXGs are infrequent and may demonstrate aggressive behavior. In this setting fine needle aspiration cytology is a useful tool for the initial differential diagnostic procedure and management.
authors.affiliation: Service of Pathology, Department of Pediatrics, Faculty of Medicine, Hospital de S. João, Instituto de Patologia e Imunologia da Univesidade do Porto, Portugal. hbarroca@hotmail.com
authors.forename: Helena
authors.initials: H
authors.lastname: Barroca
authors.forename: N J
authors.initials: NJ
authors.lastname: Farinha
authors.forename: Ana
authors.initials: A
authors.lastname: Lobo
authors.forename: Joaqum
authors.initials: J
authors.lastname: Monteiro
authors.forename: José Mahuel
authors.initials: JM
authors.lastname: Lopes
mesh_terms: D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D009333:Neck / Q000473:pathology* / Q000601:surgery; D012886:Skull / Q000473:pathology* / Q000601:surgery; D014972:Xanthogranuloma, Juvenile / Q000473:pathology* / Q000601:surgery