Clinical Characteristics of Severe Histiocytic Necrotizing Lymphadenitis (Kikuchi-Fujimoto Disease) in Children

Clinical features and recurrence predictors of histiocytic necrotizing lymphadenitis in Chinese children

OBJECTIVES

To characterize the clinical features and to identify the predictors of recurrence of histiocytic necrotizing lymphadenitis (HNL) in Chinese children.

STUDY DESIGN

This study retrospectively analyzed the clinical characteristics, laboratory and pathological findings, and recurrence status of children diagnosed with HNL at a single center in China from January 2018 to May 2023. Logistic regression analysis was employed to identify predictors of HNL recurrence.

RESULTS

181 Chinese children with histopathologically confirmed HNL were enrolled (121 males and 60 females). The mean age was 9.3 ± 2.9 years. The most prominent clinical features were fever (98.9%) and cervical lymphadenopathy (98.3%). Aseptic meningitis was the most frequent complication (38.5%), while hemophagocytic lymphohistiocytosis and autoimmune disease were rare (1.7% and 1.2%, respectively). Recurrence occurred in 12.7% of patients. Erythrocyte sedimentation rate (> 30 mm/h) was the significant predictors of HNL recurrence, with odds ratios of 6.107, respectively.

CONCLUSION

Our study demonstrates that fever and cervical lymphadenopathy are the most frequent clinical manifestations of HNL in Chinese children, which often coexist with aseptic meningitis. HNL patients with risk factors require follow-up for recurrence.

Clinical features of histiocytic necrotizing lymphadenitis in children

Due to its nonspecific clinical characteristics, histiocytic necrotizing lymphadenitis (HNL) is often misdiagnosed as a suppurative cervical lymphadenitis and lymphoma. Thus, this study aimed to investigate the clinical characteristics of HNL in pediatric patients. We retrospectively identified 61 patients with histopathologically confirmed HNL. Clinical and laboratory data, including age, sex, clinical manifestations, laboratory investigations, histological discoveries, treatment, and outcomes, were collected from the medical records to determine associations with extracervical lymph node (LN) involvement. The mean age of patients was 9.7 ± 2.8 years (range, 1.5-14.0 years), and the male-to-female ratio was 2.2:1. The most common systemic symptom was fever in all patients. The median pre-admission and total durations of fever were 13.0 (interquartile range [IQR]: 9.0-22.5 days) and 22.0 days (IQR: 17.0-33.0 days), respectively. Patients with temporary fever (< 2 weeks) had a higher peak temperature and were more likely to undergo LN biopsy after admission than those with a prolonged fever (≥ 2 weeks). Multivariate analysis revealed that peak temperature ≥ 40 °C was significantly associated with a longer fever duration (P = 0.023). Laboratory values showed leukopenia (68.9%), which presented more frequently in solitary cervical LNs than in extracervical LNs (82.4% vs. 52.9%, p = 0.027) in patients with prolonged fever.

CONCLUSIONS

HNL is often misdiagnosed in older children with persistent fever and lymphadenopathy, leading to unnecessary diagnostic tests and evaluations, inappropriate antibiotic administration, and mismanagement. A multidisciplinary team, including primary care providers, rheumatologists, and pathologists, can improve patient outcomes by increasing their awareness of this rare condition.

WHAT IS KNOWN

• Histiocytic necrotizing lymphadenitis (HNL) is characterized by fever, leukopenia, and neck lymphadenopathy with unknown etiology. • The lack of neutrophils or eosinophils in the histology, immunohistochemistry results help distinguish HNL from infectious causes. Although HNL is a self-limiting disease, antibiotics and steroid treatments were used inappropriately.

WHAT IS NEW

• A fever peak ≥ 40 °C was associated with a longer fever duration in HNL patients. Leukopenia presented more frequently in solitary cervical lymph node (LNs) than in extracervical LNs inpatients with prolonged fever. • Steroids are not recommended as a routine treatment, however, in some severe or relapsing cases with persistent symptoms, prednisolone (5 mg twice a day for 2 days) or other steroids (an equivalent dose of prednisolone) responded favorably.

Characterization of Kikuchi-Fujimoto Disease in Children and Risk Factors Associated with Its Course

OBJECTIVE

To outline the characteristics of Kikuchi-Fujimoto disease (KFD) in children and analyze factors associated with severe and recurring courses.

METHODS

Electronic medical records of children histopathologically diagnosed with KFD at Seoul National University Bundang Hospital from March 2015 to April 2021 were retrospectively reviewed.

RESULTS

A total of 114 cases (62 males) were identified. The mean patient age was 12.0 ± 3.5 years. Most patients came to medical attention with cervical lymph node enlargement (97.4%) and fever (85%); 62% had a high-grade fever (≥39°C). Prolonged fever (≥14 days) was seen in 44.3% and was associated with a high-grade fever (P = .004). Splenomegaly, oral ulcer, or rash was present in 10.5%, 9.6%, and 15.8%, respectively. Laboratory findings showed leukopenia, anemia, and thrombocytopenia in 74.1%, 49%, and 24%, respectively. Sixty percent of cases had a self-limited course. Antibiotics were initially prescribed in 20%. A corticosteroid was prescribed in 40% of patients and was associated with oral ulcer (P = .045) and anemia (P = .025). Twelve patients (10.5%) had a recurrence with a median interval of 19 months. No risk factor for recurrence was identified in multivariable analysis. Clinical characteristics of KFD were similar between our current and previous studies. However, antibiotics use decreased (P < .001); nonsteroidal anti-inflammatory drugs use increased (P < .001), and, although statistically not significant, corticosteroid treatment also increased.

CONCLUSIONS

Over a span of 18 years, the clinical characteristics of KFD did not change. Patients presenting with high-grade fever, oral ulcer, or anemia may benefit from corticosteroid intervention. All patients should be monitored for recurrence.

Elevated serum IFN-γand IFN-γ/IL-6 ratio in Kikuchi-Fujimoto disease

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is typically a benign, self-limiting inflammatory disease. The diagnosis of KFD can be challenging for nonspecific symptoms, laboratory or imaging findings. In this study, we aimed to describe the clinical manifestations of patients with KFD and to access the potential role of serum cytokines in the diagnosis of this disease.

METHODS

Patients with KFD were retrospectively enrolled from January 2015 to November 2021 at Shenzhen Children's Hospital. Clinical data were collected from inpatient or outpatient medical records. Serum cytokines were detected by the Flowcytomix technique. Serum levels of cytokines were compared between patients with KFD and SJIA, or patients with KFD and KD. The data of patients without MAS were further analyzed. A receiver operating characteristic (ROC) curve analysis was further performed to access the potential role of serum cytokines in the diagnosis of KFD.

RESULTS

Serum cytokines were detected in 25 (43.8%, 25/57) patients with a histological diagnosis of KFD. Compared to SJIA or KD patients, the KFD group had a significantly higher IFN-γ/IL-6 ratio and much lower levels of serum IL-6. The median level of serum IFN-γ in KFD was 41.65 pg/ml (range, 21.04-70.74 pg/ml), which was much higher than that in SJIA (median: 3.33 pg/ml, p = 0.16) or KD (median: 2.6 pg/ml, p = 0.01). After excluding patients with MAS, there was statistical significance in all comparisons of serum IFN-γ, IFN-γ/IL-6 ratio, and serum IL-6. The cutoff values of serum IFN-γ, IL-6, and IFN-γ/IL-6 ratio for differentiating KFD from SJIA were > 8.48 pg/ml, < 47.42 pg/ml, and > 0.45, respectively. The cutoff values of serum IFN-γ, IL-6, and IFN-γ/IL-6 ratio for differentiating KFD from KD were > 8.56 pg/ml, < 50.45 pg/ml, and > 0.45, respectively. The specificity of all those cutoff values for differentiating KFD from SJIA or KD was ≥ 94.7%.

CONCLUSIONS

For patients with fever of unknown etiology and lymphadenopathy, after excluding HLH or MAS, serum IFN-γ > 8.56 pg/mL and IFN-γ/IL-6 ratio > 0.45 may highly suggest the diagnosis of KFD; serum IL-6 > 50.45 pg/mL indicates that the probability of KFD may be small, and sJIA, KD, and acute infection should be excluded first.

Kikuchi-Fujimoto disease: A comprehensive review

Kikuchi-Fujimoto disease, a rare form of necrotizing lymphadenitis, is an uncommon, benign, self-limiting disorder of obscure etiology. It affects mostly young adults of both genders. Clinically, it presents with fever and lymphadenopathy of a firm to rubbery consistency frequently involving cervical lymph nodes while weight loss, splenomegaly, leucopenia, and elevated erythrocyte sedimentation rate feature in severely affected patients. Cutaneous involvement occurs in about 30%-40% of cases as facial erythema and nonspecific erythematous papules, plaques, acneiform or morbilliform lesions of great histologic heterogeneity. Both Kikuchi-Fujimoto disease and systemic lupus erythematosus share an obscure and complex relationship as systemic lupus erythematosus may occasionally precede, develop subsequently, or sometimes be associated concurrently with Kikuchi-Fujimoto disease. It is often mistaken for non-Hodgkin lymphoma while lupus lymphadenitis, cat-scratch disease, Sweet’s syndrome, Still’s disease, drug eruptions, infectious mononucleosis, and viral or tubercular lymphadenitis are other common differentials. Fine needle aspiration cytology mostly has features of nonspecific reactive lymphadenitis and immunohistochemistry studies usually show variable features of uncertain diagnostic value. Since its diagnosis is exclusively from histopathology, it needs to be evaluated more carefully; an early lymph node biopsy will obviate the need for unnecessary investigations and therapeutic trials. Its treatment with systemic corticosteroids, hydroxychloroquine, or antimicrobial agents mostly remains empirical. The article reviews clinicoepidemiological, diagnostic, and management aspects of KFD from the perspective of practicing clinicians.

Macrophage activation syndrome in children with Kikuchi-Fujimoto disease

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is typically a benign, self-limiting inflammatory disease. However, some patients may have a prolonged or recurrent disease course, or present with life-threatening complications such as macrophage activation syndrome (MAS). In this study, we aimed to describe the incidence and clinical features of MAS in KFD and to access potential laboratory markers for the diagnosis of KFD-associated MAS.

METHODS

Patients with KFD were retrospectively enrolled from January 2015 to November 2021 at Shenzhen Children's Hospital. Clinical data were collected from inpatient or outpatient medical records. Data collected included clinical manifestations, laboratory and imaging findings, treatment, and clinical outcomes. Data were analyzed using GraphPad Prism 8.0 statistical software (GraphPad Software Inc., La Jolla, CA, USA). A receiver operating characteristic (ROC) curve analysis was further performed to access the potential predictors for the KFD-MAS diagnosis.

RESULTS

Of 58 patients with a histological diagnosis of KFD, 15 (25.9%) patients had MAS. Compared to patients without MAS, patients with KFD-MAS presented with a higher proportion of skin rash (26.7%, p = 0.01), glucocorticoid treatment (80%, p = 0.003), and disease recurrence (33.3%, p = 0.04). KFD-MAS patients had lower absolute peripheral white blood cell (WBC, p = 0.02), platelet (p = 0.002), serum albumin levels (p = 0.01), and lymphocyte count (p < 0.0001), and higher lactate dehydrogenase (LDH) levels (p < 0.0001). ROC curve analysis showed that the cutoff values of absolute lymphocyte count, an absolute platelet count, serum albumin level, and serum LDH level for KFD-MAS diagnosis were < 1235/μL, < 171 × 10⁶/μL, < 35.6 g/L, and > 679 IU/mL, respectively.

CONCLUSIONS

The presence of KFD-MAS in children may be more common than previously expected, especially in those with skin rash. KFD-MAS may be associated with a higher recurrence rate. An extremely elevated serum LDH level and moderate to severe lymphopenia may be useful diagnostic markers for MAS in KFD.

TRIAL REGISTRATION

Not applicable; this was a retrospective study.

Clinical scoring approach for detection of histiocytic necrotising lymphadenitis in adults

BACKGROUND

Histiocytic necrotising lymphadenitis (HNL) is rare and can be easily ignored.

AIMS

To summarise the characteristics of HNL and find a simple scoring approach to detect HNL in adult patients.

METHODS

Adult patients with lymphadenopathy diagnosed by lymph node biopsy were enrolled. Chi-squared test and t-test were used to determine the significant variables. The cut-off values and scores assigned to each factor were performed by receiver operating characteristic (ROC) curves and coefficients in the logistic regression respectively. The performance of the scoring system was evaluated by ROC curves.

RESULTS

There were 32 HNL cases and 1162 other cases in the present study. These features, including age, the frequency of presentations of fever, cervical and painful lymph nodes, decrease of white blood cells (WBC), ratio of neutrophil to WBC (N ratio) and elevated lactate dehydrogenase (LDH), were different between patients with HNL and other diseases. Based on the multivariate analysis, the scoring approach was defined as follows: score = 3 (fever) + 2 (cervical lymphadenopathy) + 2 (decreased WBC) + 1 (decreased N ratio) + 2 (elevated LDH). The cut-off was score 4. This approach performed will detect HNL with an area under the curve of 0.889.

CONCLUSION

The present study suggests that the novel scoring approach we put forward might be useful to detect HNL in adult patients though further studies are needed.

Comparison of Clinical Characteristics and Risk Factors for Recurrence of Kikuchi-Fujimoto Disease Between Children and Adult

Purpose

Kikuchi-Fujimoto disease (KFD) is a rare, benign, and self-limited disease, characterized by cervical lymphadenopathy and fever. Herein, we analyzed the differences in its clinical manifestations and risk factors for recurrence between children and adults.

Patients and Methods

We retrospectively reviewed the medical records of patients diagnosed with KFD at a tertiary referral hospital between 2005 and 2019. Patients were divided into two groups based on their age: children (<19 years) and adults (≥19 years).

Results

During the 14-year study period, 127 patients were diagnosed with KFD. Among these, 34 (26.8%) were children and 93 (73.2%) were adults. The fever duration was longer and the frequency of myalgia was higher in adults than in children; however, no other significant symptomatic differences were noted between the two groups. Lymph node evaluation was mainly performed using ultrasound in children (61.8%) and computed tomography in adults (78.5%). Moreover, the frequency of antibiotic use was higher in children than in adults (76.5% vs 54.8%, P = 0.027). In adults, multivariable logistic regression analysis revealed anti-nuclear antibody (ANA) positivity (titer ≥1:80) as a risk factor for recurrence (odds ratio: 7.813; 95% confidence interval = 1.818-33.333; P = 0.006).

Conclusion

The clinical features of KFD in children and adults were similar; however, the preferred imaging study and frequency of antibiotic use differed significantly between the two groups. Furthermore, in adults, ANA positivity was associated with KFD recurrence. Thus, patients with KFD who present with ANA positivity at diagnosis will benefit from a regular follow-up for monitoring KFD recurrence.

A Malignant Mimicker: Features of Kikuchi-Fujimoto Disease in the Pediatric Population

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is a rare, benign, and self-limited disease that presents with cervical lymphadenopathy and systemic symptoms. Histologic evaluation is often necessary to differentiate KFD from other entities.

METHODS

Electronic medical records and diagnostic material were reviewed for 14 children diagnosed with KFD and 6 children diagnosed with infectious mononucleosis (IM) from 2013-2021. Four cases of KFD were further characterized using targeted DNA-based next-generation sequencing.

RESULTS

Systemic symptoms were present in 86% (n = 12/14) of KFD patients, the most common being fever. Laboratory values worrisome for malignancy included cytopenia(s) (n = 9/12), elevated ESR and/or CRP (n = 9/12), elevated ferritin (n = 7/7), and elevated LDH (n = 7/10). Histologically, lymph nodes showed characteristic necrotic foci without neutrophils surrounded by MPO+ "crescentic" histiocytes. Immunoblasts and CD123+ plasmacytoid dendritic cells (pDCs) were also increased surrounding the necrosis. IM lymph nodes showed similar features when necrosis was present but increases in pDCs were patchy and rare neutrophils were seen in the necrotic foci. Molecular analysis of 4 KFD cases did not identify pathogenic variants.

CONCLUSION

While the signs/symptoms of KFD are worrisome, there are pathologic features that help differentiate it from potential mimics. We did not identify characteristic molecular features to aid in the work-up of these cases.

Fever of unknown origin (FUO) in children: a single-centre experience from Beijing, China

OBJECTIVE

To date, there is no standard diagnostic practice to identify the underlying disease-causing mechanism for paediatric patients suffering from chronic fever without any specific diagnosis, which is one of the leading causes of death in paediatric patients. Therefore, we aimed this retrospective study to analyse medical records of paediatric patients with fever of unknown origin (FUO) to provide a preliminary basis for improving the diagnostic categories and facilitate the treatment outcomes.

DESIGN

A retrospective study.

SETTING

Beijing Children's Hospital.

PARTICIPANTS

Clinical data were collected from 1288 children between 1 month and 18 years of age diagnosed with FUO at Beijing Children's Hospital between January 2010 and December 2017.

INTERVENTIONS

According to the aetiological composition, age, duration of fever and laboratory examination results, the diagnostic strategies were analysed and formulated.

PRIMARY AND SECONDARY OUTCOME MEASURES

The statistical analyses were carried out using SPSS V.24.0 platform along with the χ² test and analysis of variance (p<0.05).

RESULTS

The duration of fever ranged from 2 weeks to 2 years, with an average of 6 weeks. There were 656 cases (50.9%) of infectious diseases, 63 cases (4.9%) of non-infectious inflammatory diseases (NIIDs), 86 cases (6.7%) of neoplastic diseases, 343 cases (26.6%) caused by miscellaneous diseases and 140 cases (10.9%) were undiagnosed. With increasing age, the proportion of FUO from infectious diseases gradually decreased from 73.53% to 44.21%. NIID was more common in children over 3 years old, and neoplastic diseases mainly occurred from 1 to 6 years of age. Among miscellaneous diseases, the age distribution was mainly in school-aged children over 6 years. Respiratory tract infection was the most common cause of FUO in children, followed by bloodstream infections. Bacterial infection was the most common cause in children with less than 1 year old, while the virus was the main pathogen in children over 1 year old.

CONCLUSIONS

The diagnosis of neoplastic diseases and miscellaneous diseases-related diseases still depends mainly on invasive examination. According to our clinical experience, the diagnostic process was formulated based on fever duration and the type of disease. This process can provide a guide for the diagnosis and treatment of paediatric FUO in the future.

Histiocytic Necrotizing Lymphadenitis with Cupriavidus Pauculus Infection in a Patient with Graves Hyperthyroidism: A Case Report

Histiocytic necrotizing lymphadenitis (HNL) is a self-limiting inflammatory disease presenting with fever and cervical lymphadenopathy. However, no case of HNL with confirmed bacterial infection has been reported. A 38-year-old man was admitted to our hospital owing to an intermittent fever from 8 days. He was diagnosed with Graves hyperthyroidism 3 months prior and began taking methimazole tablets orally. Physical examination revealed superficial lymphadenopathy and goiter of the thyroid (grade II). Blood routine showed a decrease in peripheral blood cells, including significant reduction in leukocytes and platelets. A bone marrow culture identified a very rare pathogen, Cupriavidus pauculus, but the antibiotic effect of meropenem was unsatisfactory. Biopsy of the left cervical lymph node revealed HNL, and the patient had no fever after using glucocorticoids. This case report indicates that clinicians should be aware of the coexistence of HNL and bacterial infections, especially in patients with Graves hyperthyroidism.

Kikuchi Disease in Children: Case Report and Review of the Literature

BACKGROUND

Kikuchi disease (KD) is a rare and generally benign condition of uncertain etiology that presents with nonspecific symptoms including fever and cervical lymphadenopathy. Clinical presentations can vary. Here, we present an atypical case of KD in a 10-year-old girl, as well as an updated literature review of the clinical presentation, laboratory features and management of KD in children.

METHODS

Studies (published up until February 2020) were identified through searches of PubMed using the following search items: Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis or Kikuchi disease. Our primary search resulted in 1117 publications. A total of 34 publications with a total of 670 patients were included in the final analysis.

RESULTS

All children present with lymphadenopathy. Almost all (96.3%) have cervical lymphadenopathy. Fever is recorded in the majority of children (77.1%). Analysis of laboratory features found that the majority of children have leukopenia (56.0%) and a raised erythrocyte sedimentation rate (56.0%). Over 30% have a raised C-reactive protein and anemia. Other features such as leukocytosis, thrombocytopenia and antinuclear antibodies positivity are less common. KD is mostly self-limiting, but steroids, hydroxychloroquine and intravenous immunoglobulin are used in protracted courses. Their efficacy has yet to be established in clinical trials.

CONCLUSIONS

The presentation of KD is variable, and there is no specific set of symptoms or laboratory features that reliably establishes the diagnosis. Thus, histopathology is crucial. Definitive evaluation and establishment of effective treatments will require future prospective research studies for a more comprehensive description of the clinical course and effects of treatment. Given the rarity of the disease, this will have to be performed in collaborative consortia.

Differential Diagnosis of Histiocytic Necrotizing Lymphadenitis and Malignant Lymphoma with Simple Clinical Findings

It is desirable that noninvasive differential diagnosis takes place without lymph node biopsy for histiocytic necrotizing lymphadenitis (HNL) or malignant lymphoma (ML). In this study, we propose a novel scoring model for the differential diagnosis of these diseases using clinical information and clinical findings. We retrospectively analyzed the data from 15 HNL and 13 ML pediatric patients. First, a univariate analysis identified 14 clinical factors with significant differences. Second, a subsequent analysis using receiver operating characteristic (ROC) curve analysis identified three factors among them with area under the ROC curve values of >0.95: body temperature (°C), maximum lymph node size (cm), and serum β₂-microglobulin level (mg/L). Finally, the cut-off values of each of these three factors were determined and examined for the 28 cases. All 15 HNL cases were within 2–3 of the cut-off values among the three factors, no ML case was within two or more cut-off values. Thus, the diagnostic sensitivity and specificity of this novel scoring system were both 100%, indicating that clinical scoring with body temperature, maximum lymph node size, and β₂-microglobulin are useful for distinguishing between HNL and ML.

Kikuchi Cervical Lymphadenitis in Children: Ultrasound Differentiation From Common Infectious Lymphadenitis

OBJECTIVES

To investigate ultrasound (US) features of enlarged cervical lymph nodes (LNs) to differentiate between Kikuchi disease (KD) and other common types of infectious lymphadenitis in an East Asian pediatric patient population.

METHODS

A total of 142 pediatric patients with KD and 45 patients with infectious lymphadenitis (suppurative lymphadenitis [n = 29], nontuberculous mycobacterial lymphadenitis [n = 9], and tuberculous lymphadenitis [n = 7]) were included. The clinical characteristics, laboratory results, and US features of LNs were reviewed. The area under the curve (AUC) from a receiver operating characteristic curve analysis was used as a diagnostic accuracy measure.

RESULTS

A multiple clustered adjacent pattern, bilaterality, an even size, posterior neck involvement, no enlargement, an elongated-to-ovoid shape, homogeneous hypoechogenicity, a well-defined margin, presence of an echogenic fatty hilum, no intranodal gross necrosis, increased perinodal fat echogenicity, and no increased echogenicity of the adjacent sternocleidomastoid muscle were significant US features of the affected LNs to discriminate KD from infectious lymphadenitis (P < .05). Homogeneous hypoechogenicity in KD showed the highest AUC (0.930) as a single variable (95% confidence interval, 0.88-0.96). The AUCs were increased in 3 combination models with 2 US features: homogeneous echogenicity and 1 of 3 other US features (increased perinodal fat echogenicity, 0.935; number of affected LNs, 0.947; and LN shape, 0.949).

CONCLUSIONS

Homogeneous hypoechogenicity of LNs was a significant US feature with the highest diagnostic accuracy in differentiating KD from common infectious lymphadenitis on a univariate analysis. In the combination model, US features of an elongated-to-ovoid shape and homogeneous hypoechogenicity showed the highest diagnostic accuracy.

Splenic uptake on FDG PET/CT correlates with Kikuchi-Fujimoto disease severity

Kikuchi-Fujimoto disease (KFD) is usually self-limiting, but prolonged systemic symptoms often result in frequent hospital visits, long admission durations, or missed workdays. We investigated the role of fluorine-18 fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing KFD severity. We reviewed the records of 31 adult patients with pathologically confirmed KFD who underwent ¹⁸F-FDG PET/CT between November 2007 and April 2018 at a tertiary-care referral hospital. Disease severity was assessed using criteria based on clinical manifestations of advanced KFD. Systemic activated lymph nodes and severity of splenic activation were determined using semi-quantitative and volumetric PET/CT parameters. The median of the mean splenic standardized uptake value (SUV_mean) was higher in patients with severe KFD than those with mild KFD (2.38 ± 1.18 vs. 1.79 ± 0.99, p = 0.058). Patients with severe KFD had more systemically activated volume and glycolytic activity than those with mild KFD (total lesion glycolysis: 473.5 ± 504.4 vs. 201.6 ± 363.5, p = 0.024). Multivariate logistic regression showed that myalgia (odds ratio [OR] 0.035; 95% confidence interval [CI] 0.001–0.792; p = 0.035), total lymph node SUV_max (cutoff 9.27; OR 24.734; 95% CI 1.323–462.407; p = 0.032), and spleen SUV_mean (cutoff 1.79; OR 37.770; 95% CI 1.769–806.583; p = 0.020) were significantly associated with severe KFD. ¹⁸F-FDG PET/CT could be useful in assessing KFD severity.

Kikuchi-Fujimoto Disease Triggered by Systemic Lupus Erythematosus and Mycoplasma pneumoniae Infection-A Report of a Case and a Review of the Literature

ABSTRACT

Kikuchi-Fujimoto disease (KFD) is a necrotizing histiocytic lymphadenitis that was described for the first time in 1972 in Japan. Its etiology is still not fully understood. It has been reported in association with many different agents, diseases, and triggering factors without any conclusive result. To the best of our knowledge, we report for the first time a case of KFD with systemic lupus erythematosus in a child in association with a polymerase chain reaction (PCR)-positive throat swab for Mycoplasma pneumoniae. Although difficult to prove, the acute M. pneumoniae infection might have served as a triggering event for the development of KFD in our case. We encourage further studies to investigate a potential relationship between KFD and M. pneumoniae, which should also use PCR-based testing for this pathogen in patients with KFD.

Clinical and Laboratory Characteristics of Kikuchi-Fujimoto Disease According to Age

Background: Little information exists regarding the differences in the clinical and laboratory characteristics of Kikuchi-Fujimoto disease (KFD) according to age. Objective: To evaluate the clinical and laboratory characteristics of KFD according to age. Methods: The relevance of sex, age, clinical features, laboratory findings, courses, and follow-up results were retrospectively evaluated in patients diagnosed with KFD at Pusan National University Hospital between 2010 and 2020. Results: Eighty patients (46 children and 34 adults) with a mean age of 21.5 ± 11.8 years (range, 3-49 years) were included in the study. Those aged 10-19 years accounted for the largest number of patients (42.5%). Among children, the male sex ratio was higher, especially for patients aged ≤ 9 years. In adults, the female sex ratio was higher, especially for patients aged 20-29 years. Fever, tenderness in the lymph node, and skin rashes were more common in children, while myalgia and weight loss were more common in adults. In children, the recurrence rate was significantly higher among boys than among girls (15.8 vs. 0.0%, P = 0.001); lower platelet count and higher CRP levels were observed among boys than among girls. EBV and ANA positivity rates were higher in boys than in girls. In adults, the recurrence rate was significantly higher in women than in men (18.2 vs. 0.0%, P = 0.005). ANA positivity rates were higher in women than in men. Conclusion: The clinical features, laboratory findings, and recurrence of KFD may differ depending on age and sex. Clinicians should be aware of this.

Histiocytic Necrotizing Lymphadenitis Mimicking Acute Appendicitis in a Child: A Case Report

Background: Histiocytic necrotizing lymphadenitis, also known as Kikuchi-Fujimoto disease (KFD), is a self-limiting inflammatory disease with low incidence and high misdiagnosis rate in children. Furthermore, cases where the clinical presentation resembles acute appendicitis are very rare. Case Presentation: A 14-year-old boy was misdiagnosed as acute appendicitis and received operative treatment at his early visit. He suffered from abdominal pain, vomiting, diarrhea, fever, and lymphadenitis at the ileocecal junction, which were found by B-ultrasonography examination and surgery. Lymphadenectomy, as well as appendectomy, was performed, and KFD was identified by pathological examination. The patient was transferred to our hospital for further therapy because of recurrent fever and abdominal pain after the appendectomy. His temperature became normal after methylprednisolone was administered, and no recurrence was observed till now during follow-up. Conclusions: Necrotizing lymphadenitis involving mesenteric lymph nodes may cause acute-appendicitis-like symptom; KFD should be a diagnostic consideration for mesenteric lymphadenitis.

Necrotizing lymphadenitis : A case report and literature review

BACKGROUND

Necrotizing lymphadenitis is a rare disease. It is often misdiagnosed because of the lack of typical clinical manifestations. It is worth noting that necrotizing lymphadenitis may be a precursor lesion of systemic lupus erythematosus or tumours, so regular follow-up is needed to facilitate early diagnosis. Here, we report a case and conduct a literature analysis summarizing the clinical features of necrotizing lymphadenitis and its treatment and management practices.

CASE PRESENTATION

A 16-year-old young woman presented with fever and lymphadenopathy as the main clinical manifestations, accompanied by a rash during fever that disappeared as the fever subsided. After completing imaging and laboratory examinations, we excluded other diseases such as infections, autoimmune diseases, and malignant tumours. Finally, we diagnosed the patient with necrotizing lymphadenitis based on the results of lymph node biopsy. The symptoms of the patient improved after glucocorticoid treatment, and she was followed up for half a year without recurrence of symptoms.

CONCLUSION

In the clinic, young women with fever and lymphadenopathy as major symptoms should be screened for necrotizing lymphadenitis to facilitate early diagnosis and treatment. Although necrotizing lymphadenitis is self-limiting, its clinical manifestations are similar to those of many diseases. Therefore, it is easily misdiagnosed. An in-depth understanding of the disease is conducive to early diagnosis and treatment in the clinic, thereby reducing further damage to the body and reducing unnecessary evaluation and treatment.

Risk Assessment of Recurrence and Autoimmune Disorders in Kikuchi Disease

Purpose

Kikuchi disease (KD) is typically a benign disease. Recent studies reporting recurrence or serious cases suggest a possible association of KD with systemic autoimmune disorders. We performed a long-term analysis of the characteristics of KD in patients of all ages and assessed KD recurrence or progress to systemic autoimmune disorders.

Patients and Methods

Electronic medical records of patients diagnosed with KD between April 1995 and May 2017 were reviewed for clinical and laboratory manifestations.

Results

In total, 480 patients were confirmed to have KD based on histopathology findings. The mean age at KD diagnosis was 24.4 years. Recurrence occurred in 11.3% of patients; 2.7% developed autoimmune diseases after KD diagnosis. Patients who experienced recurrence had more extranodal symptoms, lymphopenia, and a longer lymphopenia-recovery duration. Patients who developed autoimmune diseases after KD were more likely to have extranodal symptoms, KD recurrence, and anti-nuclear antibody positivity.

Conclusion

KD patients with risk factors need to be followed-up for KD recurrence and the development of systemic autoimmune diseases.

A Case of Kikuchi-Fujimoto Disease in a 7-Year-Old African American Patient: A Case Report and Review of Literature

Patient: Female, 7-year-old Final

Diagnosis: Kikuchi-Fujimoto lymphadenitis

Symptoms: Lymphadenopathy

Medication:—

Clinical Procedure: Biopsy

Specialty: Immunology • Rheumatology

Kikuchi-Fujimoto disease in children

AIM

Kikuchi-Fujimoto disease (KFD) is an important cause of lymphadenitis in children. The primary aim of this study was to investigate the clinical characteristics of children with KFD and to assess the recurrence of this disease.

METHODS

This is a retrospective study of patients younger than 18 years old, who were diagnosed with KFD from January 2000 to September 2017 at KK Women's and Children's Hospital. Records of children with a histological diagnosis of KFD from a lymph node biopsy were obtained from the Department of Pathology. Case notes and electronic medical records of the patients were reviewed. Data collected included patient characteristics, symptoms, clinical and laboratory findings, treatment and follow-up.

RESULTS

A total of 98 patients were identified. There were 52 boys and 46 girls with a median age of 11.2 years old. Recurrence occurred in 12 (12.2%) patients. One patient developed systemic lupus erythematosus 10 years after diagnosis of KFD. Recurrent cases were more likely to be managed as an inpatient and have fever at presentation of their first episode of KFD.

CONCLUSION

In our study, KFD in children had a higher prevalence among boys, and had a recurrence rate of 12.2%, with 1% of patients developing systemic lupus erythematosus. We recommend that patients be followed up for recurrence and advised to monitor for symptoms of recurrence.

Kikuchi Disease Manifesting as Multifocal Lymphadenopathy and Splenomegaly: Ultrasonography, CT, and 18F-FDG PET/CT Findings Mimicking Lymphoma

Kikuchi disease is a type of benign, self-limiting necrotizing lymphadenitis that occurs most commonly in young women and usually manifests as palpable cervical lymph nodes and fever. Patients with an unusual location of lymph node involvement can be misdiagnosed with malignant disease. Here, we report a case of Kikuchi disease in a 15-year-old girl presenting with persistent fever for 2 weeks. Imaging studies, including ultrasonography, CT, and ¹⁸F-fluorodeoxyglucose PET/CT, revealed splenomegaly and enlarged lymph nodes in the neck, axilla, abdomen, retroperitoneum, and inguinal region. Laparoscopic excision of the celiac lymph nodes confirmed histiocytic necrotizing lymphadenitis, also known as Kikuchi disease. Conservative treatment with corticosteroids improved the patient's condition.

Distribution of lymphadenopathy in patients with Kikuchi disease

BACKGROUND

Cervical lymphadenopathy is among the cardinal manifestations of Kikuchi disease (KD). The incidences and locations of extra-cervical lymph nodes (LNs) involvement in KD have not been comprehensively reported.

METHODS

From 2003 to 2016, 60 patients with pathologically confirmed KD and with computed tomography and/or whole-body inflammation scans at diagnosis were retrospectively identified. The locations, sizes and characteristics of all affected LNs were analyzed by extensive review of the image studies. The clinical and laboratory parameters were abstracted from medical records and the associations with extra-cervical LNs involvement were identified.

RESULTS

Female accounted for 35 (58.3%) patients and the median age of all patients was 21.3 years (ranges, 3-64 years). Of 59 patients with evaluable neck images, 42 (71.2%) and 16 (27.1%) patients presented with unilateral and bilateral nodal involvement, respectively, with the most common locations at level II, III and IV by Som's classification. The largest LNs appeared most commonly in level II. The incidences of extra-cervical lymphadenopathy in abdomen, pelvis, inguina, axilla and mediastinum with available images were respectively 52.9% (9/17), 47.1% (8/17), 41.2% (7/17), 30.6% (11/36) and 14.3% (8/56). When compared to cases with solitary cervical lymphadenopathy, the cases with extra-cervical lymphadenopathy had significantly greater incidences of bilateral cervical lymphadenopathy (P = .0379) and leukopenia (P = .0173).

CONCLUSION

Unilateral cervical lymphadenopathy was the most frequent form of LNs involvement of KD. Extra-cervical lymphadenopathy was not uncommon and was associated with the appearance of bilateral distribution of cervical LNs and leukopenia.

Noncaseating suppurative granulomatous lymphadenitis in adult onset Still's disease - a diagnostic dilemma in a tuberculosis-endemic region: a case report

Background

Lymphadenopathy is not an uncommon presentation of adult onset Still’s disease: it is present in up to two thirds of patients with adult onset Still’s disease. The characteristic appearance of lymphadenopathy is described as intense, paracortical immunoblastic hyperplasia. Changes in light microscopy may resemble lymphoma, but immunohistochemistry reveals a benign polyclonal B cell hyperplasia.

Case presentation

We describe a 67-year-old Sri Lankan woman who manifested relapsing prolonged fever, raised inflammatory markers, arthralgia, myalgia, transient skin rash, and cervical lymphadenopathy histologically characterized by noncaseating granulomatous adenitis with central suppuration. Due to the fact of high prevalence of tuberculosis in the region, an extensive diagnostic evaluation was done to exclude the possibility of extrapulmonary tuberculosis; unsuccessful therapeutic trials of complete antituberculosis regime reliably excluded the possibility of tuberculosis and strengthened the diagnostic validity. Disease flares were characterized by systemic inflammatory response syndrome with immediate clinical and laboratory response to corticosteroids. After systematic diagnostic workup which ruled out possible malignant, rheumatic, or autoimmune diseases and infections previously described as causes of granulomatous adenitis, our patient was diagnosed as having adult onset Still’s disease based on Yamaguchi criteria. She required a trial of indomethacin followed by methylprednisolone pulse therapy and long-term maintenance steroid therapy without steroid-sparing immunosuppressive agents or biological disease-modifying antirheumatic drugs. She achieved full disease remission in 3 months. Reevaluation after 6 months and 1 year did not reveal residual disease activity.

Conclusions

To the best of our knowledge this is the first report of suppurative noncaseating granulomatous lymphadenitis attributed to adult onset Still’s disease among Asian or South Asian ethnicities and it is also rarely reported among Europeans and North Americans. It is an extremely challenging situation to diagnose Still’s disease with granulomatous lymphadenitis where tuberculosis is highly prevalent. This case highlights the importance of consideration of adult onset Still’s disease as a potential diagnosis in a compatible clinical context in the presence of noncaseating granulomatous adenitis and indicates that one should not be misled into a diagnosis of tuberculosis by the fact of the high prevalence of tuberculosis, however, the exclusion of other diagnoses is a prerequisite.

Kikuchi-Fujimoto disease in children: two case reports and a review of the literature

BACKGROUND

Kikuchi-Fujimoto disease is a rare, idiopathic and generally self-limiting cause of lymphadenitis of unknow etiology with a low recurrence rate. The typical clinical signs are cervical lymphadenopathy, fever, and symptoms of respiratory infection, and less frequently chills, night sweats, arthralgia, rash, and weight loss.

CASE PRESENTATION

Here we describe two case reports of Kikuchi Fujimoto disease presenting in Milan within the space of a few months. The first involved the recurrence of KFD in a young boy from Sri Lanka; the second was a rare case of severe KFD complicated by HLH.

CONCLUSIONS

Pediatricians must consider KFD in the differential diagnosis of fever of unknown origin in children, even in western countries. Although rare, recurrence and severe complications are possible. Where symptoms suggest KFD, a systematic diagnostic approach is key. Since no guidelines on the management of KFD are available, further studies should be conducted to investigate the therapeutic options and long term outcome in children.

Histiocytic Necrotizing Lymphadenitis Involving the Neck: Radiology-Pathology Correlation

Histiocytic necrotizing lymphadenitis is an uncommon autoimmune condition characterized by fever, leukopenia, and neck swelling. Diagnostic imaging, including ultrasound and CT, typically demonstrates conglomerates of enlarged cervical lymph nodes with hypervascular cortices and areas of necrosis. Ultimately, the diagnosis is confirmed with the histopathologic findings of paracortical coagulative necrosis with karyorrhectic debris, abundant histiocytes, and absence of neutrophils. Other potential etiologies, such as other causes of infectious lymphadenitis, tuberculosis, lymphoma, and systemic lupus erythematosus, must be excluded. These features are exemplified in this sine qua non radiology-pathology correlation article.

Association Kikuchi disease with Hashimoto thyroiditis: a case report and literature review

Kikuchi-Fujimoto disease (KFD) is a benign and self-limited disease characterized by fever and lymphadenopathy. The etiology of KFD is unknown, but an autoimmune cause has been suggested. Hashimoto thyroiditis is the most common autoimmune thyroid disorder in children and is known to be associated with other autoimmune diseases. Only a few cases of Hashimoto thyroiditis associated with KFD have been documented. We report a case of a 16-year-old girl who was first diagnosed with KFD and developed Hashimoto thyroiditis 2 years and 6 months later during her follow-up period. Physicians of patients with KFD should consider the possibility of autoimmune diseases like Hashimoto's thyroiditis.

Pediatric Kikuchi-Fujimoto disease: A clinicopathologic study and the therapeutic effects of hydroxychloroquine

BACKGROUND

To investigate the clinical features of Kikuchi-Fujimoto disease (KFD) in children, and place an emphasis on the therapeutic effects of hydroxychloroquine as monotherapy.

METHODS

We retrospectively reviewed the medical records of all children diagnosed with KFD during the period January 1992 to September 2016 at a tertiary medical center in Taiwan.

RESULTS

40 patients were histopathologically confirmed as KFD, and the mean age of the patients was 13.9 ± 3.1 years. The male to female ratio was 1:1. The lymph node involvements were often cervical (95%) with features of unilateral predisposition (75%), polyadenopathy (84.4%) and tenderness (56.3%). Fever, cough, rhinorrhea, and tonsillitis were other common presentations. Laboratory findings included leukopenia (56.5%), monocytosis (63.6%), with positive results of EB-VCA IgG (88.9%), EB-VCA IgM (22.2%), EBEA IgG (22.2%) and EBNA IgG (88.9%). The univariate analyses of prolonged fever with lymphopenia, monocytosis, thrombocytopenia and necrotizing type in histopathology were disclosed as statistically significant (P < 0.05). Corticosteroids and hydroxychloroquine were administered in 15.6% of patients respectively, along with symptomatic treatments for the rest. Recurrence occurred in 13.0% of patients without corticosteroids or hydroxychloroquine treatment. There were neither recurrences nor relevant major adverse effects in all the five KFD cases treated with hydroxychloroquine.

CONCLUSION

KFD should be suspected in children with febrile cervical lymphadenopathy, especially when concomitant with leukopenia and monocytosis. Lymphopenia, monocytosis, thrombocytopenia and necrotizing type in histopathology are reliable predictors for prolonged fever. Hydroxychloroquine may be an alternative choice to corticosteroids for its favorable effects and safety.

The incidence and clinical characteristics by gender differences in patients with Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease (KFD) is a rare, self-limiting disorder that typically affects the cervical lymph nodes (LNs). Although initially described in young women, KFD also occurs in men. There are no reports on the clinical manifestations and characteristics of male KFD patients. Therefore, this study was conducted to assess the incidence of KFD among males, as well as the most frequent clinical characteristics of these patients. A retrospective, cross-sectional study was performed at a tertiary hospital of patients pathologically confirmed as having KFD from LN biopsy specimens. Clinical and laboratory data, and treatment outcomes of the enrolled patients, were analyzed by gender. A total of 254 patients diagnosed with KFD were enrolled. There were 189 females and 65 males (2.9:1). The mean age was 32.6 ± 11.3 years. Compared to the female patients, the males had more frequent manifestations of fever (48% vs 67%, P = 0.008), headache (9% vs 20%, P = 0.013), bilateral lymphadenopathy (31% vs 46%, P = 0.029), thrombocytopenia (14% vs 29%, P = 0.014), elevated C-reactive protein (CRP) (35% vs 78.4%, P < 0.001), elevated liver enzymes (15% vs 41%, P < 0.001), and elevated lactate dehydrogenase (LDH) (61% vs 80%, P = 0.021). Male patients had fewer autoimmune features (9% vs 2%, P = 0.043) and fewer positive antinuclear antibodies (32% vs 10%, P = 0.006). In this study, 25.6% of the enrolled patients were male, with a 2.9:1 female-to-male sex ratio. Male patients showed a distinctive profile characterized by a higher frequency of fever, headache, bilateral lymphadenopathy, and thrombocytopenia, as well as elevated liver enzymes, CRP, and LDH.

Fever of Unknown Origin in Childhood

Childhood fever of unknown origin (FUO) is most often related to an underlying infection but can also be associated with a variety of neoplastic, rheumatologic, and inflammatory conditions. Repeated, focused reviews of patient history and physical examination are often helpful in suggesting a likely diagnosis. Diagnostic workup should be staged, usually leaving invasive testing for last. Advances in molecular genetic techniques have increased the importance of these assays in the diagnosis of FUO in children.

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children

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 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%).

Conclusion

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.