Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children 1 2 1 Ji Young Kim , Hyunju Lee , Bo La Yun 1 2 Departments of Radiology and Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea ORIGINAL ARTICLE https://doi.org/10.14366/usg.16047 pISSN: 2288-5919 • eISSN: 2288-5943 Ultrasonography 2017;36:66-70 Purpose: 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 Received: September 29, 2016 were retrospectively reviewed. Localized symptoms, systemic symptoms, and laboratory findings Revised: December 1, 2016 including the white blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein Accepted: December 2, 2016 Correspondence to: (CRP) were analyzed. An analysis of the USG findings included evaluation of the location, size, Ji Young Kim, MD, Department of and presence of intranodal abscess; intranodal calcification; perinodal fat swelling; localized fluid Radiology, Seoul National University collection; and loss of nodal echogenic hilum. Bundang Hospital, 82 Gumi-ro 173beon-gil, Bundang-gu, Seongnam Results: Among the patients, 49 (58%) showed localized tenderness at the cervical 13620, Korea lymphadenopathy. Fever was present in 55 (66%), while 27 (32%) had prolonged fever. Of 74 Tel. +82-31-787-7609 with lab results, 54 (73%) had leukopenia but none had leukocytosis. Among the same 74, there Fax. +82-31-787-4011 E-mail: [email protected] 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, This is an Open Access article distributed under the 98%), and perinodal fat swelling (n=55, 65%) were common USG findings in the children with terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ Kikuchi. In addition, multiple cervical lymph nodes showed a relatively even size distribution licenses/by-nc/3.0/) which permits unrestricted non- commercial use, distribution, and reproduction in (n=73, 87%). any medium, provided the original work is properly Conclusion: The common USG findings of Kikuchi disease in the pediatric population of our cited. study were multiple conglomerated unilateral cervical lymphadenopathy showing perinodal fat Copyright © 2017 Korean Society of swelling and even size distribution. Ultrasound in Medicine (KSUM) Keywords: Histiocytic necrotizing lymphadenitis; Ultrasonography; Pediatrics Introduction How to cite this article: Kikuchi disease, also known as Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis is Kim JY, Lee H, Yun BL. Ultrasonographic findings of Kikuchi cervical lymphadenopathy a rare, benign, self-limiting cause of cervical lymphadenopathy [1,2]. Kikuchi disease has various in children. Ultrasonography. 2017 Jan;36(1): clinical features with a wide spectrum from absence of systemic symptoms to severe systemic 66-70. Ultrasonography 36(1), January 2017 e-ultrasonography.org 66 USG finding of Kikuchi cervical lymphadenopathy symptoms such as prolonged fever, arthralgia, and hemophagocytic of heat; systemic symptoms such as fever; and physical findings lymphohistiocytosis [2-6]. Among these various clinical features of including hepatomegaly or splenomegaly were all analyzed. To Kikuchi disease, cervical lymphadenopathy is the one of the most evaluate the incidence of prolonged fever lasting more than 2 common clinical findings [7]. weeks, we also evaluated the duration of the fever. For the analysis No specific laboratory tests are available for the diagnosis of of laboratory findings, we excluded 10 patients whose laboratory Kikuchi disease. Because Kikuchi disease is a benign and self- findings were unavailable. Therefore, the total number of patients limiting disease, early proper diagnosis is important in order to included in the laboratory finding analysis was 74. The laboratory avoid unnecessary evaluations for various other causes of cervical findings for evaluating leukopenia (white blood cell count <4,000/ 3 3 lymphadenopathy and unnecessary treatment such as antibiotics. mm ), leukocystosis (white blood cell count >10,000/mm ), high Kikuchi disease could be confirmed by histopathological findings erythrocyte sedimentation rate (ESR, >50 mm/h), and high level of of lymph node (LN) biopsy under ultrasonographic (USG) guidance C-reactive protein (CRP, >5 mg/dL) were also analyzed. [8]. However, biopsy is an invasive procedure with several potential complications and is difficult to conduct in children due to the need Ultrasonography and Ultrasonographically Guided Gun for admission or sedation. The delay in diagnosis could lead to Biopsy frequent hospital visits, additional costs for evaluation, and school Ultrasonography was performed using a single ultrasonography absenteeism. system, the iU22 (Philips Healthcare, Bothell, WA, USA) equipped Although several studies have reported the computed tomography with a linear high-frequency probe (5-14 MHz). Ultrasonographically (CT) or magnetic resonance imaging (MRI) findings of Kikuchi guided gun biopsies were performed using a disposable, 18-gauge, cervical lymphadenopathy [7,9,10], CT and MRI are not the usual double-action, spring-activated needle (1.1- or 1.6-cm excursion, imaging modalities used in children due to the radiation hazard and TSK Ace-cut, Create Medic, Yokohama, Japan). After local anesthesia the need for sedation. Instead, USG imaging is the most commonly with 1% lidocaine, the end of the biopsy needle was advanced into used modality for evaluating cervical lymphadenopathy in children. the cortex of the LN using a free-hand technique, after which the However, to our knowledge, no large-scale analysis of USG findings stylet and cutting cannula of the needle were fired sequentially. of Kikuchi cervical lymphadenopathy in children has been reported. The need for sedation was determined according to the patient’s Therefore, the purpose of this study is to describe the USG cooperation. findings of cervical lymphadenopathy due to Kikuchi disease in children. Image Analysis Two radiologists (J.Y.K. and B.L.Y.) retrospectively reviewed the USG findings and drew conclusions by consensus. The following USG Materials and Methods findings were analyzed: (1) location of the cervical lymphadenopathy (bilateral vs. unilateral and the level of cervical LNs); (2) distribution Patient Population This study was approved by our Institutional Review Board, and of the cervical lymphadenopathy (conglomerated vs. multiple informed consent was waived due to the retrospective design. separated); (3) the presence of intranodal gross abscess and We reviewed the electronic medical records and histopathological calcification; (4) the loss of central echogenic nodal hilum; (5) the records of patients at our institution between April 2007 and presence of perinodal fat swelling; (6) the presence of loculated September 2016. A total of 530 children ≤18 years old had fluid collection; and (7) size distribution of LNs. The author also undergone an ultrasonographically guided gun biopsy for cervical measured the long diameter (LD) and short diameter (SD) of the lymphadenopathy. Of them, 87 children were histopathologically largest cervical LN, and the ratios of LD to SD of the lesions (LD/SD) confirmed with Kikuchi disease. Among them, three children who did were calculated. We defined an enlarged LN as an LN with an SD of not undergo a full USG examination for re-evaluating both cervical more than 10 mm. chains were excluded. Ultimately, 84 children histopathologically confirmed with Kikuchi disease were enrolled in this study. Results Analysis of Clinical Findings Clinical Findings Clinical characteristics, associated symptoms, and laboratory findings The patient’s clinical findings are summarized in Table 1. The were collected from the medical records. Age and sex; localized mean age of 84 children with Kikuchi disease was 12.9±3.2 years symptoms including LN tenderness or erythema or a sensation (standard deviation), and the age range was 5-18 years old. The e-ultrasonography.org Ultrasonography 36(1), January 2017 67 Ji Young Kim, et al. results showed even sex distribution of Kikuchi disease, with a USG Findings female to male ratio of 1:1. In the children aged 10 or younger The USG findings of Kikuchi disease in children are summarized in (n=19), the sex ratio was 13:6. Of all 84 patients, 49 patients (58%) Table 2. All 84 children had multiple LNs. Most of the patients (n=72, had localized tenderness at the cervical lymphadenopathy. However, 86%) showed unilateral neck involvement. Among them, left side only one (1%) child showed localized erythema and 11 children neck involvement (45 of 72, 63%) was more common than right (13%) had a sensation of heat. Fever was present in 55 (66%), side. Bilateral neck involvement was found in 12 (14%). The most and the median duration of fever was 9 days (interquartile range, common site of Kikuchi lymphadenopathy involvement was the 0.25 to 17.0). In addition, 27 children (32%) showed prolonged area at the cervical LN level V, posterior triangle (n=77, 92%). Other fever (more than a 2-week duration). A few children presented with frequently affected node levels were level IV (n=63, 75%), III (n=63, hepatomegaly (n=2, 2%) or splenomegaly (n=4, 5%). 75%), and II (n=60, 71%). Conglomerated nodal distribution (n=57, In the 74 patients with laboratory findings, 54 (73%) had 68%) was more common than separate LN (Fig. 1). According to leukopenia. The remaining 20 of 74 patients (27%) had a white our results, most cervical LN of Kikuchi disease preserved their blood cell count in normal range. No one was found to have central echogenic hilum on ultrasonography (n=82, 98%). Perinodal leukocytosis. A high ESR (>50 mm/hr) was found in 10 patients fat swelling (n=55, 65%) was a relatively common USG finding in (14%) and a high CRP level (>5 mg/dL) in seven (9%). Kikuchi children (Fig. 2). Because perinodal fat swelling was caused by perinodal edema, the echogenicity of the swollen perinodal fat was increased on USG imaging. No cases showed intranodal abscess, intranodal calcification, or perinodal fluid collection on ultrasonography. Multiple cervical LN showed a relatively even size distribution (n=73, 87%). The mean SD and LD of the largest Table 1. Clinical and laboratory finding of Kikuchi disease in children cervical LN were 8.5 mm (range, 4 to 21 mm) and 18.7 mm (range, Clinical and laboratory finding No. of patients (%) (n=84) Age (yr) 12.9±3.2 (5-18) Table 2. USG findings of Kikuchi disease in children Sex USG finding No. of patients (%) (n=84) Female 42 (50) Location Male 42 (50) Unilateral 72 (86) Localized symptoms Right 27 LN tenderness 49 (58) Left 45 LN erythema 1 (1) Bilateral 12 (14) LN sense of heat 11 (13) Distribution Systemic symptoms Conglomerated 57 (68) Fever 55 (66) Separated 27 (32) Prolonged fever (≥2 wk) 27 (32) Intranodal abscess 00 Hepatomegaly 2 (2) Intranodal calcification 00 Splenomegaly 4 (5) Loss of central echogenic hilum 02 (2) a) Laboratory findings Perinodal fat swelling 55 (65) 3 3 WBC (4×10 /mm ) 3.3±1.5 (1.0-6.9) Perinodal fluid collection 00 Leukopenia (WBC <4,000/mm ) 54 (73) Size distribution of cervical LN ESR (mm/hr) 32±21 (3-116) Even 73 (87) High ESR (>50 mm/hr) 10 (14) Uneven 11 (13) CRP (mg/dL) 2.1±3.1 (0.01-17) Size of largest cervical LN High CRP (>5 mg/dL) 7 (9) SD (mm) 8.5±3.2 (4-21) Values are presented as numbers of patients (%) or mean±standard deviation LD (mm) 18.7±6.4 (7-40) (range). SD/LD ratio 0.5±0.1 (0.2-0.7) LN, lymph node; WBC, white blood cell count; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein. Values are presented as numbers of patients (%) or mean±standard deviation a) Patients whose laboratory findings were unavailable for analysis were excluded: (range). total number for laboratory findings=74. USG, ultrasonographic; LN, lymph node; SD, short diameter; LD, long diameter. Ultrasonography 36(1), January 2017 e-ultrasonography.org 68 USG finding of Kikuchi cervical lymphadenopathy Fig. 1. Kikuchi cervical lymphadenopathy in a 10-year-old male. Longitudinal sonogram shows multiple well-defined, conglomerated Fig. 2. Kikuchi cervical lymphadenopathy in a 5-year-old male. A lymph nodes in right cervical lymph node levels II, III, IV, and V. The longitudinal sonogram shows multiple conglomerated lymph nodes size of the cervical lymph nodes shows even distribution. It should in the left cervical jugular chain. The perinodal fat swelling with be noted that the central echogenic hilum of the cervical lymph increased echogenicity (arrows) should be noted. nodes is preserved. 7 to 40 mm), respectively. Among the patients, 22 had multiple Although leukopenia is helpful in the diagnosis of Kikuchi disease enlarged LNs. A large number of patients (62 of 84, 74%) did not because of its distinctive laboratory findings, findings of the ESR or have any LNs enlarged to a diameter of more than 10 mm. The CRP may not contribute much to the differential diagnosis because mean SD to LD ratio was 0.5±0.1 (standard deviation). they can be associated with other inflammatory diseases. Radiological findings can be helpful in diagnosing Kikuchi disease when the diagnosis is unclear based on clinical findings and Discussion laboratory findings. Ultrasonography, in particular, is a good option Kikuchi disease is an idiopathic disease usually characterized for diagnostic radiologic examination of cervical lymphadenopathy by self-limiting painful cervical lymphadenopathy. Cervical in pediatric patients. It presents no radiation hazard and no need lymphadenopathy of Kikuchi disease has a tendency to be located for additional sedation because of the short scan time. In a previous in the posterior cervical region [4,11]. This study also found that study of 175 adults with Kikuchi disease, perinodal echogenicity the posterior triangle (n=77, 92%) was the most common site of was reported as a characteristic finding of Kikuchi disease [13]. involvement. Therefore, when posterior cervical lymphadenopathy According to our results performed in children, perinodal fat occurs in children, Kikuchi disease should be included in the swelling with increased fat echogenicity (n=55, 65%) was a differential diagnosis. Regarding age, we found that Kikuchi disease common finding in Kikuchi disease, and this was consistent with in children commonly occurred in early adolescence. In our study, the previous studies. This is a finding that can be seen in other benign sex distribution of Kikuchi disease was even, with a male to female cervical lymphadenopathies such as infectious lymphadenitis. ratio of 1:1. However, when the age was limited to 10 years or less, However, considering the various USG findings (such as unilateral the ratio of boys to girls was 13:6, showing a male predominance. conglomerated distribution, even size distribution for cervical LN, no This result is consistent with previous reports on a pediatric intranodal abscess, and no intranodal calcification) that are more population [1]. On the other hand, in the adult population, female common in Kikuchi disease cases in this study, ultrasonography predominance is a characteristic finding of Kikuchi disease [12]. should still be helpful for identifying Kikuchi disease. Fever is one of the common systemic symptoms of Kikuchi The USG findings of Kikuchi disease revealed in this study will disease, but its severity varies [1]. According to our results, persistent help to narrow the range of differential diagnosis by examination in prolonged fever was observed in 32% up to 2 weeks, but fever was pediatric cases presented with cervical lymphadenopathy with fever. not observed in 34%. The systemic symptoms of Kikuchi disease Early diagnosis using USG findings can also reduce unnecessary include not only fever; in fact, the range of presentation and severity diagnostic and treatment costs. is broad. It is often difficult to diagnose Kikuchi disease with certain This study is a retrospective study in which clinical information clinical findings. It can be difficult even with laboratory findings. was drawn only from medical records, so it was difficult to carry out e-ultrasonography.org Ultrasonography 36(1), January 2017 69 Ji Young Kim, et al. research with only incomplete clinical information. The study was Semin Diagn Pathol 1988;5:329-345. 4. Lee KY, Yeon YH, Lee BC. Kikuchi-Fujimoto disease with prolonged also limited by the fact that the color Doppler exam images could fever in children. Pediatrics 2004;114:e752-e756. not be analyzed because few of the USG exams included color 5. Kim YM, Lee YJ, Nam SO, Park SE, Kim JY, Lee EY. Hemophagocytic Doppler imaging. syndrome associated with Kikuchi's disease. J Korean Med Sci In conclusion, the common USG findings of Kikuchi disease in our 2003;18:592-594. pediatric population study were multiple conglomerated unilateral 6. Chen JS, Chang KC, Cheng CN, Tsai WH, Su IJ. Childhood cervical lymphadenopathy showing perinodal fat swelling and even hemophagocytic syndrome associated with Kikuchi's disease. size distribution. Haematologica 2000;85:998-1000. 7. Kwon SY, Kim TK, Kim YS, Lee KY, Lee NJ, Seol HY. CT findings ORCID: Ji Young Kim: http://orcid.org/0000-0003-1466-2112; Hyunju Lee: in Kikuchi disease: analysis of 96 cases. AJNR Am J Neuroradiol http://orcid.org/0000-0003-0107-0724; Bo La Yun: http://orcid.org/0000-0002- 2004;25:1099-1102. 5457-7847 8. Kang HM, Kim JY, Choi EH, Lee HJ, Yun KW, Lee H. Clinical characteristics of severe histiocytic necrotizing lymphadenitis Conflict of Interest (Kikuchi-Fujimoto disease) in children. J Pediatr 2016;171:208-212. No potential conflict of interest relevant to this article was reported. 9. Na DG, Chung TS, Byun HS, Kim HD, Ko YH, Yoon JH. Kikuchi disease: CT and MR findings. AJNR Am J Neuroradiol 1997;18:1729-1732. References 10. Fulcher AS. Cervical lymphadenopathy due to Kikuchi disease: US 1. Seo JH, Shim HS, Park JJ, Jeon SY, Kim JP, Ahn SK, et al. A clinical and CT appearance. J Comput Assist Tomogr 1993;17:131-133. study of histiocytic necrotizing lymphadenitis (Kikuchi's disease) in 11. Chen CK, Low Y, Akhilesh M, Jacobsen AS. Kikuchi disease in Asian children. Int J Pediatr Otorhinolaryngol 2008;72:1637-1642. children. J Paediatr Child Health 2006;42:104-107. 2. Chuang CH, Yan DC, Chiu CH, Huang YC, Lin PY, Chen CJ, et 12. Kucukardali Y, Solmazgul E, Kunter E, Oncul O, Yildirim S, Kaplan M. Kikuchi-Fujimoto disease: analysis of 244 cases. Clin Rheumatol al. Clinical and laboratory manifestations of Kikuchi's disease in children and differences between patients with and without 2007;26:50-54. prolonged fever. Pediatr Infect Dis J 2005;24:551-554. 13. Yoo JL, Suh SI, Lee YH, Seo HS, Kim KM, Shin BK, et al. Gray scale 3. Dorfman RF, Berry GJ. Kikuchi's histiocytic necrotizing lymphadenitis: and power Doppler study of biopsy-proven Kikuchi disease. J an analysis of 108 cases with emphasis on differential diagnosis. Ultrasound Med 2011;30:957-963. Ultrasonography 36(1), January 2017 e-ultrasonography.org http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Ultrasonography Pubmed Central

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children

Ultrasonography , Volume 36 (1) – Dec 2, 2016

Loading next page...
 
/lp/pubmed-central/ultrasonographic-findings-of-kikuchi-cervical-lymphadenopathy-in-4dPYjlQosF

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Pubmed Central
Copyright
Copyright © 2017 Korean Society of Ultrasound in Medicine (KSUM)
ISSN
2288-5919
eISSN
2288-5943
DOI
10.14366/usg.16047
Publisher site
See Article on Publisher Site

Abstract

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children 1 2 1 Ji Young Kim , Hyunju Lee , Bo La Yun 1 2 Departments of Radiology and Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea ORIGINAL ARTICLE https://doi.org/10.14366/usg.16047 pISSN: 2288-5919 • eISSN: 2288-5943 Ultrasonography 2017;36:66-70 Purpose: 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 Received: September 29, 2016 were retrospectively reviewed. Localized symptoms, systemic symptoms, and laboratory findings Revised: December 1, 2016 including the white blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein Accepted: December 2, 2016 Correspondence to: (CRP) were analyzed. An analysis of the USG findings included evaluation of the location, size, Ji Young Kim, MD, Department of and presence of intranodal abscess; intranodal calcification; perinodal fat swelling; localized fluid Radiology, Seoul National University collection; and loss of nodal echogenic hilum. Bundang Hospital, 82 Gumi-ro 173beon-gil, Bundang-gu, Seongnam Results: Among the patients, 49 (58%) showed localized tenderness at the cervical 13620, Korea lymphadenopathy. Fever was present in 55 (66%), while 27 (32%) had prolonged fever. Of 74 Tel. +82-31-787-7609 with lab results, 54 (73%) had leukopenia but none had leukocytosis. Among the same 74, there Fax. +82-31-787-4011 E-mail: [email protected] 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, This is an Open Access article distributed under the 98%), and perinodal fat swelling (n=55, 65%) were common USG findings in the children with terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ Kikuchi. In addition, multiple cervical lymph nodes showed a relatively even size distribution licenses/by-nc/3.0/) which permits unrestricted non- commercial use, distribution, and reproduction in (n=73, 87%). any medium, provided the original work is properly Conclusion: The common USG findings of Kikuchi disease in the pediatric population of our cited. study were multiple conglomerated unilateral cervical lymphadenopathy showing perinodal fat Copyright © 2017 Korean Society of swelling and even size distribution. Ultrasound in Medicine (KSUM) Keywords: Histiocytic necrotizing lymphadenitis; Ultrasonography; Pediatrics Introduction How to cite this article: Kikuchi disease, also known as Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis is Kim JY, Lee H, Yun BL. Ultrasonographic findings of Kikuchi cervical lymphadenopathy a rare, benign, self-limiting cause of cervical lymphadenopathy [1,2]. Kikuchi disease has various in children. Ultrasonography. 2017 Jan;36(1): clinical features with a wide spectrum from absence of systemic symptoms to severe systemic 66-70. Ultrasonography 36(1), January 2017 e-ultrasonography.org 66 USG finding of Kikuchi cervical lymphadenopathy symptoms such as prolonged fever, arthralgia, and hemophagocytic of heat; systemic symptoms such as fever; and physical findings lymphohistiocytosis [2-6]. Among these various clinical features of including hepatomegaly or splenomegaly were all analyzed. To Kikuchi disease, cervical lymphadenopathy is the one of the most evaluate the incidence of prolonged fever lasting more than 2 common clinical findings [7]. weeks, we also evaluated the duration of the fever. For the analysis No specific laboratory tests are available for the diagnosis of of laboratory findings, we excluded 10 patients whose laboratory Kikuchi disease. Because Kikuchi disease is a benign and self- findings were unavailable. Therefore, the total number of patients limiting disease, early proper diagnosis is important in order to included in the laboratory finding analysis was 74. The laboratory avoid unnecessary evaluations for various other causes of cervical findings for evaluating leukopenia (white blood cell count <4,000/ 3 3 lymphadenopathy and unnecessary treatment such as antibiotics. mm ), leukocystosis (white blood cell count >10,000/mm ), high Kikuchi disease could be confirmed by histopathological findings erythrocyte sedimentation rate (ESR, >50 mm/h), and high level of of lymph node (LN) biopsy under ultrasonographic (USG) guidance C-reactive protein (CRP, >5 mg/dL) were also analyzed. [8]. However, biopsy is an invasive procedure with several potential complications and is difficult to conduct in children due to the need Ultrasonography and Ultrasonographically Guided Gun for admission or sedation. The delay in diagnosis could lead to Biopsy frequent hospital visits, additional costs for evaluation, and school Ultrasonography was performed using a single ultrasonography absenteeism. system, the iU22 (Philips Healthcare, Bothell, WA, USA) equipped Although several studies have reported the computed tomography with a linear high-frequency probe (5-14 MHz). Ultrasonographically (CT) or magnetic resonance imaging (MRI) findings of Kikuchi guided gun biopsies were performed using a disposable, 18-gauge, cervical lymphadenopathy [7,9,10], CT and MRI are not the usual double-action, spring-activated needle (1.1- or 1.6-cm excursion, imaging modalities used in children due to the radiation hazard and TSK Ace-cut, Create Medic, Yokohama, Japan). After local anesthesia the need for sedation. Instead, USG imaging is the most commonly with 1% lidocaine, the end of the biopsy needle was advanced into used modality for evaluating cervical lymphadenopathy in children. the cortex of the LN using a free-hand technique, after which the However, to our knowledge, no large-scale analysis of USG findings stylet and cutting cannula of the needle were fired sequentially. of Kikuchi cervical lymphadenopathy in children has been reported. The need for sedation was determined according to the patient’s Therefore, the purpose of this study is to describe the USG cooperation. findings of cervical lymphadenopathy due to Kikuchi disease in children. Image Analysis Two radiologists (J.Y.K. and B.L.Y.) retrospectively reviewed the USG findings and drew conclusions by consensus. The following USG Materials and Methods findings were analyzed: (1) location of the cervical lymphadenopathy (bilateral vs. unilateral and the level of cervical LNs); (2) distribution Patient Population This study was approved by our Institutional Review Board, and of the cervical lymphadenopathy (conglomerated vs. multiple informed consent was waived due to the retrospective design. separated); (3) the presence of intranodal gross abscess and We reviewed the electronic medical records and histopathological calcification; (4) the loss of central echogenic nodal hilum; (5) the records of patients at our institution between April 2007 and presence of perinodal fat swelling; (6) the presence of loculated September 2016. A total of 530 children ≤18 years old had fluid collection; and (7) size distribution of LNs. The author also undergone an ultrasonographically guided gun biopsy for cervical measured the long diameter (LD) and short diameter (SD) of the lymphadenopathy. Of them, 87 children were histopathologically largest cervical LN, and the ratios of LD to SD of the lesions (LD/SD) confirmed with Kikuchi disease. Among them, three children who did were calculated. We defined an enlarged LN as an LN with an SD of not undergo a full USG examination for re-evaluating both cervical more than 10 mm. chains were excluded. Ultimately, 84 children histopathologically confirmed with Kikuchi disease were enrolled in this study. Results Analysis of Clinical Findings Clinical Findings Clinical characteristics, associated symptoms, and laboratory findings The patient’s clinical findings are summarized in Table 1. The were collected from the medical records. Age and sex; localized mean age of 84 children with Kikuchi disease was 12.9±3.2 years symptoms including LN tenderness or erythema or a sensation (standard deviation), and the age range was 5-18 years old. The e-ultrasonography.org Ultrasonography 36(1), January 2017 67 Ji Young Kim, et al. results showed even sex distribution of Kikuchi disease, with a USG Findings female to male ratio of 1:1. In the children aged 10 or younger The USG findings of Kikuchi disease in children are summarized in (n=19), the sex ratio was 13:6. Of all 84 patients, 49 patients (58%) Table 2. All 84 children had multiple LNs. Most of the patients (n=72, had localized tenderness at the cervical lymphadenopathy. However, 86%) showed unilateral neck involvement. Among them, left side only one (1%) child showed localized erythema and 11 children neck involvement (45 of 72, 63%) was more common than right (13%) had a sensation of heat. Fever was present in 55 (66%), side. Bilateral neck involvement was found in 12 (14%). The most and the median duration of fever was 9 days (interquartile range, common site of Kikuchi lymphadenopathy involvement was the 0.25 to 17.0). In addition, 27 children (32%) showed prolonged area at the cervical LN level V, posterior triangle (n=77, 92%). Other fever (more than a 2-week duration). A few children presented with frequently affected node levels were level IV (n=63, 75%), III (n=63, hepatomegaly (n=2, 2%) or splenomegaly (n=4, 5%). 75%), and II (n=60, 71%). Conglomerated nodal distribution (n=57, In the 74 patients with laboratory findings, 54 (73%) had 68%) was more common than separate LN (Fig. 1). According to leukopenia. The remaining 20 of 74 patients (27%) had a white our results, most cervical LN of Kikuchi disease preserved their blood cell count in normal range. No one was found to have central echogenic hilum on ultrasonography (n=82, 98%). Perinodal leukocytosis. A high ESR (>50 mm/hr) was found in 10 patients fat swelling (n=55, 65%) was a relatively common USG finding in (14%) and a high CRP level (>5 mg/dL) in seven (9%). Kikuchi children (Fig. 2). Because perinodal fat swelling was caused by perinodal edema, the echogenicity of the swollen perinodal fat was increased on USG imaging. No cases showed intranodal abscess, intranodal calcification, or perinodal fluid collection on ultrasonography. Multiple cervical LN showed a relatively even size distribution (n=73, 87%). The mean SD and LD of the largest Table 1. Clinical and laboratory finding of Kikuchi disease in children cervical LN were 8.5 mm (range, 4 to 21 mm) and 18.7 mm (range, Clinical and laboratory finding No. of patients (%) (n=84) Age (yr) 12.9±3.2 (5-18) Table 2. USG findings of Kikuchi disease in children Sex USG finding No. of patients (%) (n=84) Female 42 (50) Location Male 42 (50) Unilateral 72 (86) Localized symptoms Right 27 LN tenderness 49 (58) Left 45 LN erythema 1 (1) Bilateral 12 (14) LN sense of heat 11 (13) Distribution Systemic symptoms Conglomerated 57 (68) Fever 55 (66) Separated 27 (32) Prolonged fever (≥2 wk) 27 (32) Intranodal abscess 00 Hepatomegaly 2 (2) Intranodal calcification 00 Splenomegaly 4 (5) Loss of central echogenic hilum 02 (2) a) Laboratory findings Perinodal fat swelling 55 (65) 3 3 WBC (4×10 /mm ) 3.3±1.5 (1.0-6.9) Perinodal fluid collection 00 Leukopenia (WBC <4,000/mm ) 54 (73) Size distribution of cervical LN ESR (mm/hr) 32±21 (3-116) Even 73 (87) High ESR (>50 mm/hr) 10 (14) Uneven 11 (13) CRP (mg/dL) 2.1±3.1 (0.01-17) Size of largest cervical LN High CRP (>5 mg/dL) 7 (9) SD (mm) 8.5±3.2 (4-21) Values are presented as numbers of patients (%) or mean±standard deviation LD (mm) 18.7±6.4 (7-40) (range). SD/LD ratio 0.5±0.1 (0.2-0.7) LN, lymph node; WBC, white blood cell count; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein. Values are presented as numbers of patients (%) or mean±standard deviation a) Patients whose laboratory findings were unavailable for analysis were excluded: (range). total number for laboratory findings=74. USG, ultrasonographic; LN, lymph node; SD, short diameter; LD, long diameter. Ultrasonography 36(1), January 2017 e-ultrasonography.org 68 USG finding of Kikuchi cervical lymphadenopathy Fig. 1. Kikuchi cervical lymphadenopathy in a 10-year-old male. Longitudinal sonogram shows multiple well-defined, conglomerated Fig. 2. Kikuchi cervical lymphadenopathy in a 5-year-old male. A lymph nodes in right cervical lymph node levels II, III, IV, and V. The longitudinal sonogram shows multiple conglomerated lymph nodes size of the cervical lymph nodes shows even distribution. It should in the left cervical jugular chain. The perinodal fat swelling with be noted that the central echogenic hilum of the cervical lymph increased echogenicity (arrows) should be noted. nodes is preserved. 7 to 40 mm), respectively. Among the patients, 22 had multiple Although leukopenia is helpful in the diagnosis of Kikuchi disease enlarged LNs. A large number of patients (62 of 84, 74%) did not because of its distinctive laboratory findings, findings of the ESR or have any LNs enlarged to a diameter of more than 10 mm. The CRP may not contribute much to the differential diagnosis because mean SD to LD ratio was 0.5±0.1 (standard deviation). they can be associated with other inflammatory diseases. Radiological findings can be helpful in diagnosing Kikuchi disease when the diagnosis is unclear based on clinical findings and Discussion laboratory findings. Ultrasonography, in particular, is a good option Kikuchi disease is an idiopathic disease usually characterized for diagnostic radiologic examination of cervical lymphadenopathy by self-limiting painful cervical lymphadenopathy. Cervical in pediatric patients. It presents no radiation hazard and no need lymphadenopathy of Kikuchi disease has a tendency to be located for additional sedation because of the short scan time. In a previous in the posterior cervical region [4,11]. This study also found that study of 175 adults with Kikuchi disease, perinodal echogenicity the posterior triangle (n=77, 92%) was the most common site of was reported as a characteristic finding of Kikuchi disease [13]. involvement. Therefore, when posterior cervical lymphadenopathy According to our results performed in children, perinodal fat occurs in children, Kikuchi disease should be included in the swelling with increased fat echogenicity (n=55, 65%) was a differential diagnosis. Regarding age, we found that Kikuchi disease common finding in Kikuchi disease, and this was consistent with in children commonly occurred in early adolescence. In our study, the previous studies. This is a finding that can be seen in other benign sex distribution of Kikuchi disease was even, with a male to female cervical lymphadenopathies such as infectious lymphadenitis. ratio of 1:1. However, when the age was limited to 10 years or less, However, considering the various USG findings (such as unilateral the ratio of boys to girls was 13:6, showing a male predominance. conglomerated distribution, even size distribution for cervical LN, no This result is consistent with previous reports on a pediatric intranodal abscess, and no intranodal calcification) that are more population [1]. On the other hand, in the adult population, female common in Kikuchi disease cases in this study, ultrasonography predominance is a characteristic finding of Kikuchi disease [12]. should still be helpful for identifying Kikuchi disease. Fever is one of the common systemic symptoms of Kikuchi The USG findings of Kikuchi disease revealed in this study will disease, but its severity varies [1]. According to our results, persistent help to narrow the range of differential diagnosis by examination in prolonged fever was observed in 32% up to 2 weeks, but fever was pediatric cases presented with cervical lymphadenopathy with fever. not observed in 34%. The systemic symptoms of Kikuchi disease Early diagnosis using USG findings can also reduce unnecessary include not only fever; in fact, the range of presentation and severity diagnostic and treatment costs. is broad. It is often difficult to diagnose Kikuchi disease with certain This study is a retrospective study in which clinical information clinical findings. It can be difficult even with laboratory findings. was drawn only from medical records, so it was difficult to carry out e-ultrasonography.org Ultrasonography 36(1), January 2017 69 Ji Young Kim, et al. research with only incomplete clinical information. The study was Semin Diagn Pathol 1988;5:329-345. 4. Lee KY, Yeon YH, Lee BC. Kikuchi-Fujimoto disease with prolonged also limited by the fact that the color Doppler exam images could fever in children. Pediatrics 2004;114:e752-e756. not be analyzed because few of the USG exams included color 5. Kim YM, Lee YJ, Nam SO, Park SE, Kim JY, Lee EY. Hemophagocytic Doppler imaging. syndrome associated with Kikuchi's disease. J Korean Med Sci In conclusion, the common USG findings of Kikuchi disease in our 2003;18:592-594. pediatric population study were multiple conglomerated unilateral 6. Chen JS, Chang KC, Cheng CN, Tsai WH, Su IJ. Childhood cervical lymphadenopathy showing perinodal fat swelling and even hemophagocytic syndrome associated with Kikuchi's disease. size distribution. Haematologica 2000;85:998-1000. 7. Kwon SY, Kim TK, Kim YS, Lee KY, Lee NJ, Seol HY. CT findings ORCID: Ji Young Kim: http://orcid.org/0000-0003-1466-2112; Hyunju Lee: in Kikuchi disease: analysis of 96 cases. AJNR Am J Neuroradiol http://orcid.org/0000-0003-0107-0724; Bo La Yun: http://orcid.org/0000-0002- 2004;25:1099-1102. 5457-7847 8. Kang HM, Kim JY, Choi EH, Lee HJ, Yun KW, Lee H. Clinical characteristics of severe histiocytic necrotizing lymphadenitis Conflict of Interest (Kikuchi-Fujimoto disease) in children. J Pediatr 2016;171:208-212. No potential conflict of interest relevant to this article was reported. 9. Na DG, Chung TS, Byun HS, Kim HD, Ko YH, Yoon JH. Kikuchi disease: CT and MR findings. AJNR Am J Neuroradiol 1997;18:1729-1732. References 10. Fulcher AS. Cervical lymphadenopathy due to Kikuchi disease: US 1. Seo JH, Shim HS, Park JJ, Jeon SY, Kim JP, Ahn SK, et al. A clinical and CT appearance. J Comput Assist Tomogr 1993;17:131-133. study of histiocytic necrotizing lymphadenitis (Kikuchi's disease) in 11. Chen CK, Low Y, Akhilesh M, Jacobsen AS. Kikuchi disease in Asian children. Int J Pediatr Otorhinolaryngol 2008;72:1637-1642. children. J Paediatr Child Health 2006;42:104-107. 2. Chuang CH, Yan DC, Chiu CH, Huang YC, Lin PY, Chen CJ, et 12. Kucukardali Y, Solmazgul E, Kunter E, Oncul O, Yildirim S, Kaplan M. Kikuchi-Fujimoto disease: analysis of 244 cases. Clin Rheumatol al. Clinical and laboratory manifestations of Kikuchi's disease in children and differences between patients with and without 2007;26:50-54. prolonged fever. Pediatr Infect Dis J 2005;24:551-554. 13. Yoo JL, Suh SI, Lee YH, Seo HS, Kim KM, Shin BK, et al. Gray scale 3. Dorfman RF, Berry GJ. Kikuchi's histiocytic necrotizing lymphadenitis: and power Doppler study of biopsy-proven Kikuchi disease. J an analysis of 108 cases with emphasis on differential diagnosis. Ultrasound Med 2011;30:957-963. Ultrasonography 36(1), January 2017 e-ultrasonography.org

Journal

UltrasonographyPubmed Central

Published: Dec 2, 2016

There are no references for this article.