Causative agents of Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis): a meta-analysis

Kikuchi-Fujimoto disease associated with a flare-up of a leukocytoclastic vasculitis: A rare case report and review of literature

RATIONALE

Kikuchi-Fujimoto disease (KFD) also known as histiocytic necrotizing lymphadenopathy is an exceedingly rare cause of cervical lymphadenopathy, commonly accompanied by systemic symptoms such as fever, fatigue, night sweats, myalgia, skin rash.

PATIENT CONCERNS

In this paper, we report the case of a 22-year-old female patient who experienced a flare-up of leukocytoclastic vasculitis that was complicated by the appearance of a cervical lymph node with dysphagia, fever and nausea.

DIAGNOSIS

Infectious and autoimmune workup came back negative.

INTERVENTIONS

Excisional lymph node biopsy was done and the pathology results were consistent with histiocytic necrotizing lymphadenitis in keeping with Kikuchi-Fujimoto disease.

OUTCOMES

Patient improved on intravenous corticosteroids and was discharged on per os prednisone. Six month follow-up shows complete resolution of her symptoms.

LESSONS

KFD should be ruled out in patients with autoimmune or inflammatory diseases who develop lymphadenopathies.

Case report: Kikuchi-Fujimoto disease: unveiling a case of recurrent fever and enlarged cervical lymph nodes in a young female patient with a literature review of the immune mechanism

The inflammatory response to viral infection is an important component of the antiviral response, a process that involves the activation and proliferation of CD8+ T, CD4+ T, and dendritic cells; thus, viral infection disrupts the immune homeostasis of the organism, leading to an increased release of inflammatory factors. Kikuchi-Fujimoto disease (KFD) is an inflammatory self-limited disorder of unknown etiology, and it is generally believed that the pathogenesis of this disease includes two aspects: viral infection and autoimmune response. Various immune cells, such as CD8+ T lymphocytes, CD4+ T lymphocytes, and CD123+ plasmacytoid dendritic cells, as well as the cytokines they induce and secrete, such as interferons, interleukins, and tumor necrosis factors, play a crucial role in the pathogenesis of KFD. In this article, we present a case study of a young female patient from China who exhibited typical symptoms of lymph node inflammation and fever. The diagnosis of KFD was confirmed through a lymph node biopsy. She presented with elevated ESR, IL-6, and IFN-γ. Viral markers showed elevated IgG and IgM of cytomegalovirus (CMV) and elevated IgG of Epstein-Barr virus (EBV), while changes occurred in the CD4+ T and CD8+ T cell counts. Eventually, the patient achieved disease relief through steroid treatment. Based on these findings, we conducted a comprehensive review of the involvement of viral infection-induced inflammatory response processes and autoimmunity in the pathogenesis of Kikuchi-Fujimoto disease.

Kikuchi-Fujimoto Disease Following COVID-19 Vaccination: Experience at a Population-Based Referral Center

OBJECTIVES

Multiple case reports describe Kikuchi-Fujimoto disease (KFD) following COVID-19 vaccination, but the true nature of this phenomenon is unknown. The purpose of this study was to further assess the relationship between KFD and COVID-19 vaccination at the population level.

METHODS

Confirmed KFD cases from January 2018 to April 2022 were identified from provincial pathology archives and analyzed in the context of vaccination statistics from public health resources.

RESULTS

Our statistical models provide evidence of a temporal association between KFD and both antecedent COVID-19 vaccine administration as well as age-stratified vaccination rates. Eight new cases of plausible COVID-19 vaccine-associated KFD are presented, collectively exhibiting clinical and pathologic features that overlap substantially with those of idiopathic KFD.

CONCLUSIONS

Our findings indicate that KFD is observed in association with COVID-19 vaccination and suggest that mechanistic studies are warranted.

Clonal T-cell proliferations occasionally occur in Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting disorder that frequently leads to swelling of cervical lymph nodes in young women. It has a characteristic histologic appearance with sharply demarcated foci containing apoptotic debris, histiocytes, and proliferating large T-cells. Since in the past years, core needle biopsies have been increasingly used for diagnostic work-up, a small biopsy of the pathognomonic proliferating T-cell foci may lead to misinterpretation as a large T-cell neoplasia. The aim of the present study therefore was to analyze how frequently clonal T-cell receptor (TCR) amplificates may be obtained in KFD using a commonly used TCR gamma rearrangement clonality assay. In 88 KFD cases, TCR gamma clonality assays could be successfully applied. Clonal peaks of TCR gamma in front of a polyclonal background were observed in 15 cases (18%). The investigated clinical parameters (age, gender, extent of infiltration of the lymph node, percentage of proliferative compartment) did not differ between patients with detectable TCR gamma clones from those patients who had polyclonal TCR gamma results. Our study therefore demonstrates that clonal TCR gamma amplificates may be obtained in any type of KFD and that an over-interpretation of clonal T-cell proliferates in diagnostically equivocal material should be avoided.

A Rare Case of Kikuchi-Fujimoto Disease

Kikuchi-Fujimoto disease (KFD) is an autoimmune condition that is more common in females and occurs in the third decade of life. The condition is usually benign and self-resolving and is characterized by fever, cervical lymphadenopathy, night sweats, myalgia, and rashes. The disease can be misdiagnosed as reactive follicular hyperplasia, tuberculous lymphadenitis, systemic lupus erythematosus, and malignant lymphoma. The diagnosis of KFD involves the excision of the affected lymph node. Although there is no specific treatment for the disease, usually symptomatic and supportive measures are effective; however, steroids and immunosuppressive therapies are considered in more severe cases. The disease lasts for around one to four months. The neurological complications include cerebellar ataxia, meningoencephalitis, and aseptic meningitis. Here, we describe the case of a 36-year-old male who presented with complaints of fever, malaise chills, anorexia, and fatigue associated with a tender right axillary lymph node. The patient underwent a biopsy which confirmed KFD and responded well to supportive therapy.

Ankylosing spondylitis with Kikuchi-Fujimoto disease: A case report with literature review

We present the case of a patient diagnosed with ankylosing spondylitis (AS) along with Kikuchi-Fujimoto disease (KFD), possibly triggered by infection or autoimmunity. Both AS and KFD involved a similar immune pathway. Hence, clinicians should consider the possibility of KFD when lymphadenopathy is observed, especially in patients with infection or underlying autoimmune diseases.

Kikuchi-Fujimoto-like lymphadenopathy following COVID-19 vaccine: diagnosis and management

A woman in her mid 40s presented for breast imaging after 1 week of painful and enlarged right axillary lymphadenopathy. She denied history of fever, weight loss, night sweats fatigue, cat scratch or other trauma. She received the second dose of Pfizer COVID-19 vaccine 3 months previously on the contralateral arm. A mammogram demonstrated a single, asymmetric, large and dense right axillary lymph node. Ultrasound confirmed a 2.5 cm lymph node with cortical thickening of 0.6 cm. Ultrasound-guided core biopsy showed necrotising lymphadenitis with associated aggregates of histiocytes and plasmacytoid dendritic cells. Potential causes of necrotising adenitis including Bartonella, tuberculosis, Epstein-Barr Virus, herpes simplex virus, systemic lupus erythematosus and lymphoma were excluded. In the absence of any identifiable infectious or autoimmune causes, and given the temporal relatedness with vaccine administration, it was determined that the Kikuchi-Fujimoto-like necrotising lymphadenitis was likely secondary to the COVID-19 vaccine. To date, there has been no casual association made between the COVID-19 vaccine and KFD necrotising lymphadenitis.

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-Fujimoto disease in the Eastern Mediterranean zone

Kikuchi–Fujimoto disease (KFD) is a rare benign and self-limiting syndrome. We aim to review cases of KFD at our institution as a rare illness in the Arab ethnic descent and to analyse reports from most countries in the East Mediterranean zone. This is a retrospective study in which the histopathology database was searched for the diagnosis of KFD. A full review of KFD patients’ medical records was done. Data regarding demographic features, clinical presentation, laboratory findings, comorbidities, and management protocols were obtained. Published KFD cases from east Mediterranean countries were discussed and compared to other parts of the world. Out of 1968 lymph node biopsies studied, 11 (0.6%) cases of KFD were identified. The mean age of patients with KFD was 32 years (4–59). 73% (8/11) were females. The disease was self-limiting in 5 patients (45%); corticosteroid therapy was needed in 4 patients (34%). One patient was treated with methotrexate and one with antibiotics. One patient died as a consequence of lymphoma. Jordanians and Mediterranean populations, especially those of Arab ethnic background, seem to have low rates of KFD. The genetic susceptibility theory may help to explain the significantly higher disease prevalence among East Asians. Early diagnosis of KFD—although challenging—is essential to reduce the morbidity related to this illness.

Kikuchi-Fujimoto Disease Complicated by Rheumatoid Arthritis, Type 1 Diabetes Mellitus, and Hypothyroidism

Kikuchi-Fujimoto disease (KFD) is a rare, benign, self-limited syndrome characterized by tender lymphadenopathy and low-grade fever. It may also present with rash, arthritis, fatigue, and splenomegaly. Data on the disease is limited, and its etiology remains largely unknown.

Here, we present the case of a 30-year-old female with a medical history of rheumatoid arthritis (RA), previously treated with etanercept, type 1 diabetes mellitus (DM-1), and Hashimoto’s hypothyroidism; she was brought in to an emergency department (ED) in Houston after a generalized tonic-clonic seizure and loss of consciousness. She was hypoglycemic, which was thought to have caused her DM-1 and seizure. CT scan of her chest showed multiple enlarged lymph nodes throughout the neck, superior mediastinum, and axilla, along with interstitial edema and bilateral pleural effusions. She was treated with dextrose drip and regained her consciousness. However, she had persistent pancytopenia, low-grade fever, and tender axillary lymphadenopathy. Infectious workup for tuberculosis (TB), human immunodeficiency virus (HIV), herpes simplex virus (HSV), Epstein-Barr virus (EBV), and parvovirus B-19 were negative. Her bone marrow biopsy revealed iron-deficiency anemia, while excisional axillary lymph node biopsy showed extensive necrosis consistent with KFD. She was treated with supportive care. Her neutrophilic fever resolved, and she was discharged home after 48-hours of remaining afebrile. Six months after her hospitalization, the patient remained well, and her complete blood count showed no abnormalities.

Due to the non-specific clinical features and laboratory findings of KFD, it is commonly misdiagnosed as infectious, autoimmune, or malignant lymphadenitis, leading to excessive diagnostic tests and unnecessary treatments. Physicians need to be cognizant of KFD and consider it in young patients presenting with tender lymphadenopathy, low-grade fevers, and leukopenia. To our best knowledge, this is the first reported case of a patient with concurrent RA, Hashimoto’s hypothyroidism, and KFD. This report elucidates the autoimmune nature of KFD and its association with other autoimmune diseases.

Analysis of the clinical manifestations and 18F-FDG PET-CT findings in 40 patients with histiocytic necrotizing lymphadenitis

Histiocytic necrotizing lymphadenitis (HNL) is a rare, benign, and self-limiting inflammatory disease that mainly involves the lymph nodes. There is a lack of large sample studies concerning the clinical manifestations and imaging features of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of HNL.The clinical symptoms, laboratory examination results, 18F-FDG PET/CT imaging features, and treatment outcome were investigated in this retrospective study.A total of 40 HNL patients were recruited. The onset age was between 14 and 65 years, with a median of 25 years. The white blood cell count was 3.9 (2.9, 7.1) × 109/L, C-reactive protein level was 20.2 (6.6, 63.8) mg/L, erythrocyte sedimentation rate was 29.0 (18.0,45.0) mm/h, and ferritin was 616.5 (205.6, 2118.1) ng/mL. An abnormal liver function was observed in 23 patients. 18F-FDG PET-CT showed that an abnormal lymph node metabolism was observed in 38 patients, among which the highest 18F-FDG maximal standard uptake value (SUVmax) of the lymph nodes ranged between 3.4 and 41.9; the nodes were mainly distributed in the neck and axilla regions. Meanwhile, a total of 2502 lymph nodes (721 lymph nodes with a short axis greater than 10 mm) were found in the 38 patients, including 1837 lymph nodes with an 18F-FDG SUVmax ≥ 2.5. The 18F-FDG SUVmax of the spleen ranged from 2.5 to 9.2 in 20 patients, while that of central and peripheral bone marrow ranged from 2.7 to 36.0 in 30 patients. After follow-up for an average period of 1 month, the symptoms improved after prednisone treatment.HNL often occurs in adolescents. Scanning with 18F-FDG PET/CT showed that most patients had multiple involved lymph nodes that were hypermetabolic, and only few lymph nodes are enlarged. Besides, the spleen or central and peripheral bone marrow could sometimes be hypermetabolic. Glucocorticoid treatment for the HNL patients is effective.

The great masquerader: Kikuchi-Fujimoto disease presenting as fever of unknown origin

INTRODUCTION

Kikuchi-Fujimoto (KF) disease, also known as necrotizing histiocytic lymphadenitis, is a rare cause of fever of unknown origin. Most commonly seen in Japanese populations, it presents with fever and diffuse lymphadenopathy. KF can present a diagnostic challenge as its presentation can mimic sepsis, autoimmune disease, and/or malignancy. We present a case of KF disease presenting with innumerable pulmonary nodules and suspected sepsis.

CASE REPORT

A 24-year old African-American male inmate with no past medical history presented to the Emergency Department with two witnessed generalized tonic-clonic seizures. Initial vitals were notable for a fever of 101.5 F, tachycardia, and tachypnea. He was lethargic with a diffuse, erythematous, scaly, necrotic rash. Additionally, cervical, axillary, and inguinal mobile, non-tender lymph nodes were noted. Laboratory studies revealed white blood cells 1.9 × 10 3 cells/μL with 25% bands, hemoglobin 9.4 G/dL, and platelet count of 110 × 10 3 cells/μL. He was subsequently admitted for sepsis due to presumed meningitis and started on broad-spectrum antibiotics. Lumbar puncture revealed no pleocytosis. Peripheral blood smear showed bandemia with Pelger Huet cells. Computed Tomography of chest, abdomen, and pelvis with contrast revealed diffuse pulmonary nodules involving all lobes of the lungs in addition to bulky hilar and retroperitoneal lymphadenopathy. Interventional Radiology performed a retroperitoneal lymph nodes biopsy that revealed lymphoplasmacytic cell infiltrate with extensive necrosis. Otolaryngology performed an excisional biopsy of a lymph node, which showed histiocytic necrotizing lymphadenitis. The final diagnosis was Kikuchi-Fujimoto disease, also known as histiocytic necrotizing lymphadenitis.

OUTCOME

The patient completed a 7-day course of empiric antibiotics. Workup for infectious etiologies was negative. The patient had a repeat CT of the chest with interval resolution of his pulmonary nodules on outpatient follow-up.

CONCLUSION

Patients with innumerable pulmonary nodules and fever of unknown origin should be evaluated early in their hospital course for KF as early diagnosis can reduce excessive testing and shorten hospital stay.

Kikuchi-Fujimoto disease involving retroperitoneal lymph nodes: An uncommon presentation

Kikuchi-Fujimoto disease is a self-limited disease of unknown etiology that is clinically defined by fevers accompanied by tender posterior cervical lymphadenopathy. It often presents acutely or sub-acutely, and due to its non-specific features, the differential diagnosis is broad and includes infectious, autoimmune, and malignant causes. Although cases of extra-cervical disease are not uncommon, involvement of retroperitoneal lymph nodes has only rarely been reported. Here, we describe a patient with Kikuchi-Fujimoto disease who presented with fever of unknown origin, abdominal pain, and enlarged hypermetabolic retroperitoneal lymph nodes.

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.

Kikuchi-Fujimoto Disease With Encephalopathy in Children: Case Reports and Literature Review

Background: Kikuchi-Fujimoto disease (KFD) is a benign and self-limiting disease characterized by regional lymphadenitis and low-grade fever. Encephalopathy may present in children with KFD. We present three cases of KFD with encephalopathy in children and a literature review. Methods: Literature published between 2010 and 2020 was reviewed to understand the clinical features, laboratory findings, and treatments for encephalopathy occurring in children with KFD. Results: The interval between KFD and onset of neurological symptoms was 10 days to 3 months. Laboratory results were normal, except for high protein levels in cerebrospinal fluid findings. Brain magnetic resonance imaging (MRI) findings include hyperintense T2 and FLAIR signal in the supratentorial white matter, deep gray matter, brain stem, cerebellum, temporal lobes, pons, and basal ganglia. Glucocorticoids and immunoglobulin could be effective for treating KFD with encephalopathy. Conclusion: The early clinical manifestations of KFD with encephalopathy in children lack specificity, and the diagnosis is mainly based on CSF analysis and brain MRI findings. Early and timely immunomodulatory therapy is effective and can improve the prognosis of patients with KFD with encephalopathy.

Development of Kikuchi-Fujimoto disease after a cervical lymph node metastasis of mucoepidermoid carcinoma: a case report

Kikuchi-Fujimoto disease (KFD) was first reported by Kikuchi and Fujimoto in 1972 as a rare disease with lymphadenitis of unknown etiology. KFD is characterized by the main symptoms of fever and enlarged cervical lymph nodes (LNs), which are similar to the features of other LN-associated diseases. Therefore, it is difficult to diagnose this condition. We report the case of a 24-year-old woman who presented with KFD after surgery to treat a mucoepidermoid carcinoma of the palate and dissection of the left neck. The patient presented with a fever and right cervical lymphadenopathy when she visited our department for a regular follow-up related to the mucoepidermoid carcinoma. The results of computed tomography and ultrasonography evaluations led to a clinical diagnosis of lymph node metastasis, and a right neck dissection was performed. However, the pathological tissue analysis did not suggest malignancy but showed necrosis and various cellular infiltrates. We made a diagnosis of KFD from these clinical and pathological features. KFD may be misdiagnosed as a LN-associated disease such as metastasis. Clinically, KFD should be considered in patients with head and neck cancer who present with cervical lymphadenopathy.

Kikuchi-Fujimoto disease complicated by aseptic meningitis and hemophagocytosis successfully treated with intrathecal dexamethasone

Kikuchi-Fujimoto disease (KFD) is thought to be a self-limited disease featuring fever and cervical lymphadenopathy; most cases having a favorable outcome. Severe disease and death are occasionally reported. Here we report a case of KFD complicated by hemophagocytosis and aseptic meningitis. The symptoms and laboratory parameters improved after systemic glucocorticoids, intravenous immunoglobulin and one dose of intrathecal dexamethasone. Clinicians should aware of this disease and make early diagnosis by lymph node biopsy to avoid over-treatment.

Identification of Torque Teno Virus/Torque Teno-Like Minivirus in the Cervical Lymph Nodes of Kikuchi-Fujimoto Lymphadenitis Patients (Histiocytic Necrotizing Lymphadenitis): A Possible Key to Idiopathic Disease

Kikuchi-Fujimoto disease (KFD) is rare, and many infectious agents have been suspected for its etiology. This report presents an interesting case of KFD found with torque teno virus/torque teno minivirus (TTV/TTMV), which closely resembles the circovirus that causes necrotizing lymphadenitis in pigs. Three Korean patients showed several enlarged lymph nodes in their neck. Quantitative polymerase chain reaction (qPCR) and subsequent DNA sequencing for TTV/TTMV using formalin-fixed paraffin-embedded tissue were performed. Histologic examination demonstrated typical features of KFD. qPCR showed successful amplification of TTV/TTMV, and DNA sequencing confirmed the results. It is the first report of TTV/TTMV presence in three patients with KFD.

Strong association of Torque teno virus/Torque teno-like minivirus to Kikuchi-Fujimoto lymphadenitis (histiocytic necrotizing lymphadenitis) on quantitative analysis

INTRODUCTION

Kikuchi-Fujimoto disease (KFD) is a rare benign lymphadenitis that mainly involves cervical lymph nodes of young Asian women with unknown etiology. Recently, we experienced a case of KFD found with Torque teno virus/Torque teno-like mini virus (TTV/TTMV) from a 26-year-old woman. TTV/TTMV is a genus of Circoviridae that causes necrotizing lymphadenitis in pigs, which shares the key histologic finding of KFD. The purpose of this study is to investigate the pathogenic role of TTV/TTMV in KFD by quantitative polymerase chain reaction (qPCR) analysis.

METHOD

We performed two-step qPCR specific to TTV/TTMV with formalin-fixed paraffin-embedded tissue of sequentially selected 100 KFD patients and 50 randomly selected, matched normal controls. Consequent direct sequencing was done for confirmation with PCR products.

RESULTS

PCR amplification of TTV and TTMV was found in a significantly higher proportion in KFDs than normal controls (TTV, 85% vs. 18%, p < 0.000; TTMV, 91% vs. 24%, p < 0.000). After the sequencing, KFD samples showed more sequence matching than control samples for TTMV (94% vs. 30%, p < 0.000).

CONCLUSION

This finding strongly suggests the possible implication of TTV/TTMV in the pathogenesis of KFD. Animal or in vivo experimental design should be followed in the future.Key Points• Kikuchi-Fujimoto disease (KFD) is rare and its etiology is still unclear.• Torque teno/Torque teno-like minivirus (TTV/TTMV) is a recently introduced virus in the Circoviridae family that causes necrotizing lymphadenitis in pigs, histologically similar to KFD.• We discovered the significantly increased TTV/TTMV viral loads in the KFD patients than normal controls, which implicates TTV/TTMV in the pathogenesis of KFD.

Kikuchi-Fujimoto Disease: A Review

Kikuchi-Fujimoto disease (KFD) is a rare entity characterized by subacute necrotizing lymphadenopathy and frequently associated with fever. Young adults of Asian ancestry are most commonly affected, but it has been reported worldwide. Despite many studies in the literature, the cause of KFD remains uncertain. Histologically, KFD is characterized by paracortical lymph node expansion with patchy, well-circumscribed areas of necrosis showing abundant karyorrhectic nuclear debris and absence of neutrophils and eosinophils. Three evolving histologic patterns-proliferative, necrotizing, and xanthomatous-have been recognized. By immunohistochemistry, histiocytes in KFD are positive for myeloperoxidase. There is a marked predominance of T cells in the lesions (with mostly CD8-positive cells) with very few B cells. The differential diagnosis of KFD includes infectious lymphadenitis, autoimmune lymphadenopathy (primarily systemic lupus erythematosus), and lymphoma. Clinicians and pathologists are poorly familiar with this entity, which frequently causes significant diagnostic challenges.

Kikuchi-Fujimoto Disease: An Atypical Presentation of a Rare Disease

Kikuchi-Fujimoto disease (KFD), or necrotizing histiocytic lymphadenitis, is a rare cause of lymphadenopathy and fever. Although the clinical course is usually benign, KFD is often mistaken for malignancy or infection. Recognition of typical and atypical cases of KFD is necessary to avoid unnecessary interventions. Here we report an atypical presentation of KFD with diffuse lymphadenopathy and leukocytosis associated with high levels of circulating Epstein-Barr viral DNA.

Kikuchi-Fujimoto disease: a rare cause of cervical lymphadenopathy and fever

A 28-year-old Pakistani man with previously treated latent tuberculosis (TB) presented with a 3-month history of productive cough, fever, drenching night sweats, anorexia, sore throat and tender left cervical lymphadenopathy. Extensive biochemical and microbiological tests, and imaging studies were all inconclusive. Lymph node biopsy revealed the diagnosis of Kikuchi-Fujimoto disease (KFD). He had persistent fever and anorexia during admission despite supportive measures which resolved quickly on starting prednisolone. He remained well after being weaned off steroids on 18 weeks' follow-up. KFD is a rare, self-limiting disease which can mimic several serious conditions such as TB and lymphoma. Prompt diagnosis with lymph node biopsy is paramount in addressing diagnostic uncertainty and avoids starting potentially toxic treatment on these patients.

Kikuchi-Fujimoto Disease in an Old Italian Woman: Case Report and Review of the Literature

Kikuchi-Fujimoto disease (KFD) is a rare, benign, generally self-limiting disease that has higher prevalence in Asian people with a few cases reported in European countries. It generally affects young subjects under 40 years of age and is characterized by regional lymphadenopathy. Here, we present a case of a 66-year-old Italian woman who was extensively examined for right unilateral laterocervical lymph nodes associated with fever, night sweats, fatigue, and weight loss. She was diagnosed as having the KFD only after an excision biopsy of the largest laterocervical lymph node and was then managed symptomatically with NSAIDs. We also made a review of the literature for better awareness of the disease among physicians especially in those countries, like Italy, where the disease is not prevalent and may be frequently misdiagnosed. In fact, to our best knowledge, only seven Italian cases of KFD have been published in the last 15 years with patients being younger than 40 years. We finally highlight that it is noteworthy to consider KFD as differential diagnosis of lymphadenopathy even in old patients, and, since a misdiagnosis of lymphoma is actually feasible, an early biopsy has to be taken into account for confirming diagnosis and helping in the timely and appropriate management.

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 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.