Characteristics of Kikuchi-Fujimoto disease in children compared with adults

Kikuchi-Fujimoto disease co-occuring with Hashimoto thyroiditis: A case report and literature review

We introduce a 16-year-old female who presented with tender cervical lymphadenopathy, prolonged fever, and hypothyroidism. After excluding common causes of fever of unknown origin, a surgical biopsy of cervical lymph nodes revealed Kikuchi-Fujimoto disease. The patient showed improvement with a short-term course of NSAIDs. An increased titre of thyroperoxidase antibody led to a diagnosis of Hashimoto's thyroiditis during stable condition. This report underscores the importance of considering Kikuchi-Fujimoto disease in the differential diagnosis of prolonged fever of unknown origin with lymphadenopathy and highlights the association with Hashimoto's thyroiditis, advocating for vigilance regarding hypothyroidism in long-term follow-up after Kikuchi-Fujimoto disease recovery.

Kikuchi-Fujimoto Disease Associated With Mycoplasma Pneumoniae Infection

Kikuchi-Fujimoto disease (KFD) is a self-limited disease that is more common in young Asian women. Typical presentations included fever and cervical lymphadenopathy. The etiology of KFD is unknown, and diagnosis is based mainly on lymph node biopsy. KFD has been reported to be associated with Mycoplasma pneumoniae infection. However, the role of antibiotic treatment is unclear. We reported 2 cases of KFD associated with Mycoplasma pneumoniae infection and were successfully treated with a macrolide.

Tender Cervical Lymphadenopathy in a Pediatric Patient

An 11-year-old boy presented with enlarged and tender cervical lymph nodes that showed areas of central hypodensity and necrosis with histiocytes and an absence of neutrophils. What is your diagnosis?

The co-occurrence of Kikuchi-Fujimoto disease and systemic lupus erythematosus: a case report

BACKGROUND

Kikuchi-Fujimoto disease is an uncommon systemic disease that mostly affects young women. Kikuchi-Fujimoto disease typically manifests as necrotizing lymphadenopathy, which frequently follows by a fever; however, Kikuchi-Fujimoto disease occurs rarely in extranodal regions. One of the most important accompaniments of Kikuchi-Fujimoto disease is its connection with autoimmune diseases such as systemic lupus erythematosus. This case presents a simultaneous occurrence of Kikuchi-Fujimoto disease with liver involvement and systemic lupus erythematosus in a young female patient.

CASE PRESENTATION

We present a rare case of a 20-year-old white woman who presented with fever, joint pains, myalgia, and shortness of breath. Initial hospitalization and treatment for fever of unknown origin did not yield improvement. Physical examination revealed cervical and supraclavicular lymphadenopathy, and laboratory investigations showed abnormal blood counts, elevated inflammatory markers, and positive autoimmune serologies. Imaging studies revealed bilateral pleural effusion and liver lesions. Lymph node biopsy confirmed the diagnosis of Kikuchi-Fujimoto disease, and liver biopsy showed extranodal involvement. The patient was diagnosed with Kikuchi-Fujimoto disease-associated systemic lupus erythematosus and treated with hydroxychloroquine and corticosteroids. The patient showed gradual resolution of symptoms and lymphadenopathy with treatment.

CONCLUSION

Kikuchi-Fujimoto disease is a rare systemic condition primarily impacting young females. It is characterized by necrotizing lymphadenopathy, often accompanied by fever. Although Kikuchi-Fujimoto disease is predominantly seen in the lymph nodes, occurrences in non-nodal areas are infrequent. When diagnosing Kikuchi-Fujimoto disease, it is essential to screen patients for systemic lupus erythematosus. In this particular case, we observed liver involvement along with the presence of both Kikuchi-Fujimoto disease and systemic lupus erythematosus.

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.

Systemic Lupus Erythematosus Lymphadenopathy Presenting as Kikuchi-Fujimoto Disease in an Adolescent

Systemic lupus erythematosus is a multisystem autoimmune disorder with a highly heterogeneous clinical presentation. The clinical phenotype varies from mild cutaneous and musculoskeletal manifestations to neurological involvement. Lymphadenopathy is a frequent manifestation of SLE, but the association is often not recognized, as lymphadenopathy is not a criterion for diagnosis. An unusual and seldom reported mimicker of lupus lymphadenitis is Kikuchi-Fujimoto Disease. This is a rare self-limiting disease of young adult females that presents with lymphadenopathy, fever, and systemic symptoms. Lupus lymphadenitis and KFD share some common clinical and pathologic features; but distinguishing between those two diseases can be challenging. We describe a 16-year-old Hispanic female who presented with axillary lymphadenopathy and was initially diagnosed with KFD based on an excisional lymph node biopsy; but later met the criteria for the 2019 European League Against Rheumatism/American College of Rheumatology classification criteria SLE. This case highlights the need for clinicians to be aware that patients with SLE may present with lymphadenopathy and to consider the association between Kikuchi disease and SLE to prevent misdiagnosis and allow for timely treatment to avoid complications.

Kikuchi Disease in Children: A Report of Two Cases

Kikuchi disease (KD) is a benign self-limiting rare disease with unknown etiology. Prolonged fever with tender neck lymphadenitis is the most common presentation. Blood tests are not specific, and the final diagnosis is by biopsy. We describe two patients, ages seven and twelve years, who presented with fever and neck lymphadenitis. Both cases received antibiotics for more than two weeks without improvement. Blood work showed high inflammatory markers. The manifestation of the second case overlapped with Hashimoto's disease. The later diagnosis was confirmed by lymph node (LN) biopsy.

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.

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.

The fine-needle aspiration cytology and clinical findings of Kikuchi-Fujimoto disease in pediatric patients: a retrospective clinical study

BACKGROUND

Histological evaluation of lymph node is crucial for the definitive diagnosis of Kikuchi-Fujimoto disease (KFD). However, lymph node biopsy under local anesthesia is often difficult in pediatric patients.

OBJECTIVES

We evaluated cytological findings for pediatric patients with prolonged cervical lymphadenitis clinically suggestive of KFD and investigated the clinical characteristics of patients diagnosed with KFD by fine-needle aspiration cytology (FNAC).

METHODS

This retrospective clinical study included 58 Japanese pediatric patients with cervical lymphadenitis who underwent FNAC.

RESULTS

Cytological diagnosis was KFD for 22 and suspicion of KFD for 11 patients. The remaining 25 patients were diagnosed with non-specific lymphadenitis (NSL). Tenderness was independently associated with a higher frequency of both KFD in narrow and broad senses, compared with NSL (p = .009; p = .038). The percentage of patients who underwent FNAC within 28 days from symptom onset tended to be higher among patients with KFD in a narrow sense than those with NSL (p = .052).

CONCLUSION

This study indicated that the period from symptom onset to FNAC (<28 days) and the symptom of tenderness were associated with the cytological diagnosis of KFD.

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.

A Rare Case of Kikuchi-Fujimoto Disease in a Young Female Patient

Patient: Female, 25-year-old

Final Diagnosis: Kikuchi-Fujimoto disease

Symptoms: Neck pain • palpable mass neck

Medication: —

Clinical Procedure: —

Specialty: Pathology • Pulmonology • Radiology

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.

Characterization of Plasmacytoid Dendritic Cells, Microbial Sequences, and Identification of a Candidate Public T-Cell Clone in Kikuchi-Fujimoto Disease

OBJECTIVES

Kikuchi-Fujimoto disease (KFD) is a self-limited lymphadenitis of unclear etiology. We aimed to further characterize this disease in pediatric patients, including evaluation of the CD123 immunohistochemical (IHC) staining and investigation of potential immunologic and infectious causes.

METHODS

Seventeen KFD cases and 12 controls were retrospectively identified, and the histologic and clinical features were evaluated. CD123 IHC staining was quantified by digital image analysis. Next generation sequencing was employed for comparative microbial analysis via RNAseq (5 KFD cases) and to evaluate the immune repertoire (9 KFD cases).

RESULTS

In cases of lymphadenitis with necrosis, >0.85% CD123+ cells by IHC was found to be six times more likely in cases with a final diagnosis of KFD (sensitivity 75%, specificity 87.5%). RNAseq based comparative microbial analysis did not detect novel or known pathogen sequences in KFD. A shared complementarity determining region 3 (CDR3) sequence and use of the same T-cell receptor beta variable region family was identified in KFD LNs but not controls, and was not identified in available databases.

CONCLUSIONS

Digital quantification of CD123 IHC can distinguish KFD from other necrotizing lymphadenitides. The presence of a unique shared CDR3 sequence suggests that a shared antigen underlies KFD pathogenesis.

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.

Kikuchi's disease with hemophagocytic lymphohistiocytosis: A case report and literature review

INTRODUCTION

Kikuchi's disease (KD) is a rare form of necrotizing lymphadenitis that rarely occurs in association with hemophagocytic lymphohistiocytosis (HLH) in children.

PATIENT CONCERNS

We report the case of a 4-year-5-month-old boy who suffered from fever, cervical lymphadenopathy, pancytopenia, hypertriglyceridemia, splenomegaly, low NK cell activity.

DIAGNOSES

A diagnosis of KD with HLH was made based on the results of biopsy of cervical lymph node and HLH-2004 trial guidelines.

INTERVENTIONS

The patient was treated with corticosteroids, cyclosporine, etoposide, continuous hemodiafiltration (HDF), and plasma exchange (PE).

OUTCOMES

He showed a complete response to therapy, and his condition gradually improved. He was discharged on day 45 after admission due to his good recovery status.

CONCLUSION

HLH can be associated with KD, especially in childhood, and may have an aggressive clinical course. Continuous HDF and PE and chemotherapy should be reserved for those patients who fail to respond to IVIG and corticosteroids.

Diagnosis of Kikuchi-Fujimoto disease in an 11-year-old girl with fever and sickle cell disease

Kikuchi-Fujimoto disease (KFD) is a rare lymphohistiocytic disorder which can cause prolonged fever and other systemic B symptoms including diffuse lymphadenopathy. Given its clinical presentation, there is often initial concern for lymphoma and diagnosis requires lymph node biopsy. It most frequently affects young women of Asian descent; it is less commonly encountered in paediatric patients. KFD is typically a benign, self-limited process, however, there is an association with development of systemic lupus erythematosus. Given its rarity, it remains unclear if KFD is associated with other chronic conditions. Here we present the third case of KFD occurring in a paediatric patient with sickle cell disease.

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.

Case Report of Kikuchi-Fujimoto Disease from Sub-Saharan Africa: An Important Mimic of Tuberculous Lymphadenitis

Kikuchi-Fujimoto disease (KFD) is a rare form of painful lymphadenopathy, usually cervical, which is more common in Southeast Asia and rarely reported from Africa. Symptoms are usually nonspecific (fever, night sweats, etc.), and can mimic more common diseases such as tuberculosis (TB) in endemic areas. We report a case of a 29-year-old black African woman who was admitted with headache, neck pain, fever, and lymphadenopathy. She was found to have aseptic meningitis, eventually attributed to TB based on cervical node biopsy, although further histology suggested KFD. Blood tests for systemic lupus erythematosus (SLE) were negative; she had already been commenced on anti-TB treatment and had responded well and so was continued with this therapy. She was also later diagnosed with Hashimoto's thyroiditis 3 months after her diagnosis of KFD. Five months after stopping TB treatment, she was readmitted with the same symptoms and associated painless lymphadenopathy. Repeat biopsy was morphologically similar to that of 2017, and repeat evaluation confirmed SLE. She has since been managed by a rheumatologist and continues to do well.

Kikuchi-Fujimoto Disease in Children: An Important Diagnostic Consideration for Cervical Lymphadenitis

Kikuchi-Fujimoto disease (KFD), or histiocytic necrotizing lymphadenitis, is a rare, benign, and self-limited disease that causes lymphadenopathy and has a characteristic histological appearance. The etiology of this disease is unknown, but a possible infectious trigger has been hypothesized. In the adult population this disease is more common in females; however, in the pediatric population it is more common in males. Descriptions in the pediatric literature are lacking, particularly in the United States. The authors report three cases of pediatric KFD that presented at the same institution in a 9-month time period. All three patients were male and of non-Asian descent who were diagnosed with KFD by histopathologic specimen after presenting with unilateral cervical lymphadenitis. Each patient had additional laboratory evidence of a possible bacterial infection at the time of diagnosis. These three cases highlight the importance of considering KFD early when a pediatric patient presents with unilateral cervical lymphadenitis. The authors discuss the epidemiology, etiology, clinical manifestations, diagnostic approaches, and treatment of KFD. [Pediatr Ann. 2019;48(10):e406-e411.].

Kikuchi-Fujimoto disease triggered by Salmonella enteritidis in a child with concurrent auto-immune thyroiditis and papilloedema

Kikuchi-Fujimoto disease (KFD) is a histiocytic necrotising lymphadenitis characterised by painful cervical lymphadenopathy, fever, malaise and weight loss. Infections, auto-immune pathogenesis and a genetic association have been implicated. A 12-year-old boy presented with a 1-month history of fever, abdominal pain, constipation and weight loss, and a painful lymph node was detected in the right axilla. Chest CT demonstrated multiple lymph nodes, especially in the left mediastinum. Salmonella enteritidis group D was detected in a blood culture and he was treated with ceftriaxone, followed by meropenem. An axillary lymph node biopsy demonstrated necrotising histiocytic lymphadenitis and KFD was diagnosed. He was discharged 35 days after admission. He was re-admitted 3 weeks later with recurrence of symptoms and headache and was found to have papilloedema of the left eye and auto-immune thyroiditis. Intravenous immunoglobulin (IVIG) 400 mg/kg/day was administered for 5 days. The fever and papilloedema slowly resolved and, subsequently, the thyroiditis, and he has remained well on follow-up. This is the first report of an association of S. enteritidis infection and papilloedema with KFD. IVIG may be required in prolonged or recurrent cases and in those with an auto-immune association.

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.

Kikuchi-Fujimoto disease in the regional lymph nodes with node metastasis in a patient with tongue cancer: A case report and literature review

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare self-limiting disorder typically affecting the cervical lymph nodes (LNs), which is often misdiagnosed as other LN-associated diseases. KFD frequently presents with necrotic lesions and recurrences, which are also features of metastatic LNs. Clinicians may thus suspect LN metastasis when they encounter ipsilateral cervical lymphadenopathy in a patient with head and neck cancer. The present study reports the case of a 48-year-old man with tongue cancer and KFD affecting the right edge of his tongue and ipsilateral cervical LNs. LN metastasis was initially suspected, but pathological examination of the dissected LNs revealed one necrotic metastatic lesion and two necrotic KFD lesions. Ipsilateral cervical lymphadenopathy recurred 6 years after the initial surgery, and it was not possible to differentiate clinically between a second primary tumor and recurrent KFD prior to treatment. To the best of our knowledge, this is the first reported case of simultaneous tongue cancer, regional LN metastasis and KFD. This highlights the requirement to consider KFD in the event of LNs with necrotic lesions but no cancerous cells. A combination of clinical and pathological approaches may aid in the diagnosis of KFD, in addition to ruling out LN metastasis in initial and recurrent lymphadenopathies. The present study indicate that a diagnosis of KFD should be considered in patients with head and neck cancer that exhibit necrotic LNs lacking cancerous cells. This is important, as misdiagnosis of KFD as LN metastasis may lead to unnecessary adjuvant therapy.

[Kikuchi-Fujimoto disease mimicking malignant lymphoma in adolescents]

Kikuchi-Fujimoto disease, also known as histiocytic necrotizing lymphadenitis, is a rare cause of lymphadenopathy in children. This benign disease can mimic lymphoma and misleads doctors. It was first described in Asia, where it occurred especially in young women. Recent publications show that it can also affect teenagers and young adults in Caucasian populations. The pathophysiology remains unknown. Three hypotheses have been raised for this disease: the role of viruses (in particular HHV-8), genetic predisposition (two alleles in HLA class II genes were found more frequently in patients with Kikuchi disease), and an autoimmune cause because of the correlation with lupus erythematosus. Few cases have been reported in Europe so far. In this article, we report three cases of Kikuchi disease observed in less than 2 months in a single hospital in France. All three patients were teenagers who presented with lymphadenopathy, either isolated or combined with fever, weakness, and weight loss. In all of them, the hypermetabolic activity of the lymph node on the PET scanner misled us to suspect lymphoma. The diagnosis of Kikuchi disease was finally made, for all patients, after 2 weeks in the hospital based on lymph node biopsy. Based on this report, we highlight that early biopsy in presence of lymphadenopathy can avoid unnecessary extensive investigations. Moreover, in this rare disease, it is very surprising to come across three cases that are not family-related, in such a short period of time. This strengthens the hypothesis of the possible implication of an environmental factor in the pathophysiology of Kikuchi disease.

Pathogenesis, diagnosis, and management of Kikuchi-Fujimoto disease

BACKGROUND

Kikuchi-Fujimoto disease (KFD) is a rare lymphohistiocytic disorder with an unknown etiopathogenesis. This disease is misdiagnosed as malignant lymphoma in up to one-third of cases and is associated with the development of systemic lupus erythematosus (SLE).

METHODS

The medical literature between the years 1972 and 2014 was searched for KFD, and the data were collected and analyzed regarding the epidemiology, clinical presentations, diagnosis, management, and suggested diagnostic and treatment algorithms.

RESULTS

Although KFD has been reported in other ethnic groups and geographical areas, it is more frequently diagnosed in young women of Asian descent. Patients with the disease typically present with rapidly evolving tender cervical lymphadenopathy, night sweats, fevers, and headache. Diagnosis is based on histopathological examination. Excisional lymph node biopsy is essential for a correct diagnosis. Apoptotic coagulation necrosis with karyorrhectic debris and the proliferation of histiocytes, plasmacytoid dendritic cells, and CD8(+) T cells in the absence of neutrophils are characteristic cytomorphology features. Interface dermatitis at the onset of KFD may be a marker for the subsequent evolution of SLE. The natural course of the disease is typically benign. Short courses of steroids, nonsteroidal anti-inflammatory drugs, or hydroxychloroquine can be administered to patients with more severe symptoms.

CONCLUSIONS

Although KFD was described more than 40 years ago, the etiology of this disease remains unsolved. Infectious or autoimmune processes were proposed but have not been definitively confirmed. Clinical presentation with systemic B symptoms and adenopathy may lead to an erroneous diagnosis of malignant lymphoma. The introduction of modern methods into hematopathology, including immunohistochemistry, flow cytometry, and molecular clonality studies, has decreased the probability of misdiagnosis. Until reliable prognostic markers are available, patients with KFD should have continued long-term follow-up care due to their increased risk of SLE.

Association between Kikuchi-Fujimoto disease and Streptococcus pneumoniae infection

Kikuchi-Fujimoto disease is a rare histiocytic necrotizing lymphadenitis that affects typically young women causing fever and painful laterocervical lymphadenopathy. The etiology is unknown, but several viral infections and autoimmune diseases have been related with the disease. Bacterial infections are less frequent. Diagnosis needs for excisional lymph node biopsy that shows paracortical areas of coagulative necrosis with abundant debris, distortion of the nodal architecture, and a large amount of histiocytes at the margins of the necrotic areas. There is no specific treatment for the disease. We present the case of a young woman with Kikuchi-Fujimoto disease associated with lower respiratory tract infection by Streptococcus pneumoniae and review the literature.

Recurrent lymphadenopathy in children with Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease (KFD) is characterized by self-limiting regional lymphadenopathy with prolonged fever. Although the reported recurrence rate of KFD is known to be 3-4 %, this rate appears to be higher in our clinical experience, and rates up to 38.5 % have been previously reported. In this retrospective study, we reviewed medical records of children with pathologically confirmed KFD to investigate the factors associated with recurrent KFD. Enrolled children were divided into two groups according to the recurrence of KFD, and clinical and laboratory factors were compared between the two groups. The recurrence of KFD was determined based not on repeated pathologic confirmation but on the presence of clinical febrile lymphadenopathy. A total of 33 children with KFD, 26 boys (78.8 %) and 7 girls (21.2 %), with a median age of 12 years (9 months to 19 years), were enrolled. Thirty-one children (93.9 %) complained of fever, and most of the children (90.9 %) complained of cervical lymphadenopathy. Neutropenia (<1,500/μL) or lymphopenia (<1,500/μL) was observed in 51.5 %. Lactate dehydrogenase level, erythrocyte sedimentation rate, and C-reactive protein level were elevated in 90.9, 96.9, and 54.5 % of children, respectively. Fourteen children (42.4 %) experienced recurrent KFD, including ten children after biopsy and four children before and after biopsy. In a multivariate analysis, a past history of other systemic illnesses (p = 0.013) and a higher absolute lymphocyte count (p = 0.023) were significantly associated with recurrent KFD. These systemic illnesses were chronic idiopathic thrombocytopenic purpura, autoimmune thyroiditis, nephrotic syndrome, perinatal cytomegalovirus infection, and hemophagocytic lymphohistiocytosis.

CONCLUSION

Our results suggest that recurrent KFD is more frequent than reported, and recurrent KFD should be considered in children with a history of other systemic illnesses such as immune disorders.