title: Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children.
abstract: OBJECTIVE
  The purpose of this study was to analyze the ultrasonographic (USG) findings of Kikuchi cervical lymphadenopathy in pediatric patients.
  
  
  METHODS
  Between April 2007 and September 2016, 84 children (42 male and 42 female; mean±standard deviation age, 12.9±3.2 years; range, 5 to 18 years) confirmed with Kikuchi disease were enrolled. Clinical findings and USG findings of Kikuchi cervical lymphadenopathy were retrospectively reviewed. Localized symptoms, systemic symptoms, and laboratory findings including the white blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were analyzed. An analysis of the USG findings included evaluation of the location, size, and presence of intranodal abscess; intranodal calcification; perinodal fat swelling; localized fluid collection; and loss of nodal echogenic hilum.
  
  
  RESULTS
  Among the patients, 49 (58%) showed localized tenderness at the cervical lymphadenopathy. Fever was present in 55 (66%), while 27 (32%) had prolonged fever. Of 74 with lab results, 54 (73%) had leukopenia but none had leukocytosis. Among the same 74, there was a high ESR (>50 mm/hr) in 10 (14%) and a high CRP level (>5 mg/dL) in seven (9%). The USG findings of most of the patients (n=72, 86%) showed unilateral neck involvement, especially in the left side neck (45 of 72, 63%). The most common site of Kikuchi lymphadenopathy involvement was the area at cervical lymph node level V, at the posterior triangle (n=77, 92%). Conglomerated nodal distribution (n=57, 68%), preserved central nodal echogenic hilum (n=84, 98%), and perinodal fat swelling (n=55, 65%) were common USG findings in the children with Kikuchi. In addition, multiple cervical lymph nodes showed a relatively even size distribution (n=73, 87%).
  
  
  CONCLUSIONS
  The common USG findings of Kikuchi disease in the pediatric population of our study were multiple conglomerated unilateral cervical lymphadenopathy showing perinodal fat swelling and even size distribution.
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ji Young
authors.identifier: 0000-0003-1466-2112
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyunju
authors.identifier: 0000-0003-0107-0724
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Bo La
authors.identifier: 0000-0002-5457-7847
authors.initials: B
authors.lastname: Yun
keywords: Histiocytic necrotizing lymphadenitis; Pediatrics; Ultrasonography