Kikuchi-Fujimoto disease, simultaneously diagnosed with systemic lupus erythematosus in an Arabic female: an agonizing combination

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare, benign condition affecting young Oriental-Asian females. It is characterized by fever and tender cervical lymphadenopathy with an unclear aetiology, and in most longitudinal reviews, KFD occurs before systemic lupus erythematosus (SLE). Herein, the case of a 28-year-old Kuwaiti female without any relevant past medical history, who was simultaneously diagnosed with KFD and SLE following an Ebstein-Barr virus infection, is reported. The patient was treated with oral prednisolone, hydroxychloroquine, cyclosporin, and belimumab and her response was clinically and biochemically favourable. Although KFD is prevalent in Asian populations, it may affect all races. Early diagnosis of KFD is difficult, particularly when simultaneously diagnosed with SLE, but crucial to preventing inappropriate therapy. Clinicians need to know about this rare disease, especially when patients present with fever and swollen lymph nodes, due to a risk of misdiagnosis with tuberculosis or lymphoma, as these are more often thought to be the cause of such symptoms.

Kikuchi disease in acute leukaemia: a distinct clinical syndrome with HLA association

AIMS

To report the clinicopathological features of Kikuchi disease in patients with acute leukaemia, emphasising similarities among cases.

METHODS AND RESULTS

In a cohort of 454 Kikuchi disease patients, we identified three cases of concurrent acute leukaemia. These patients shared similar clinical traits, with Kikuchi disease emerging approximately a month after induction chemotherapy onset, featuring neck-region lymphadenopathy. Notably, two patients were middle-aged, deviating from the typical age distribution of Kikuchi disease. Histologically, these cases aligned with typical Kikuchi disease. Negative immunohistochemical stains (CD34, CD117, ERG, TdT) indicated the absence of extramedullary leukaemic infiltration. Herpes simplex virus immunohistochemical staining was also negative. Significantly, a human leucocyte antigen (HLA) association was observed in these three cases. HLA-B*15:01, C*04:01, and DRB1*04:06 were more prevalent in these patients compared to the general population (compared with three independent control cohorts: Taiwanese Han Chinese (n = 504), Tzu Chi Taiwanese bone marrow donors (n = 364) and Hong Kong Chinese (n = 5266)).

CONCLUSIONS

Our study underscores the unique link between Kikuchi disease and acute leukaemia, characterised by specific features and HLA associations. This underlines Kikuchi disease as a possible differential diagnosis in pertinent clinical scenarios. Furthermore, this syndrome offers insights into postchemotherapy immunology in acute leukaemia, enhancing comprehension.

Distinguishing Kikuchi-Fujimoto disease from lymphoma in patients by clinical and PET/CT features

To develop a scheme for distinguishing Kikuchi-Fujimoto disease (KFD) from lymphoma in patients presenting enlarged lymph nodes (LNs) predominantly on the upper side of the diaphragm. From November 2015 to August 2023, 32 KFD patients and 38 lymphoma patients were pathologically confirmed and enrolled in this retrospectively study. Clinical and 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) features were collected. When comparing those PET/CT parameters, we set 5 models with different research objects: (1) all affected LNs; (2) the 5 largest affected LNs in terms of maximum diameter; (3) the 5 largest affected LNs in terms of maximum standard uptake values (SUVmax); (4) the largest affected LNs in terms of maximum diameter; (5) the largest affected LNs in terms of SUVmax. Compared to lymphoma patients, KFD patients were younger; and with higher incidence of fever, arthralgia, abnormal serum white blood cell, lactate dehydrogenase (LDH) and splenomegaly; lower incidence of affected LNs perinodal infiltration, necrosis and conglomeration; more affected LNs in Head and Neck nodes (particularly in level II) and Axillary in KFD (P ˂ .05). PET/CT parameters presented as various difference in each model. Finally, 11 clinical and PET/CT features (age ≤ 34, with fever, arthralgia, abnormal white blood cell, abnormal LDH, and without node necrosis and node conglomeration have a score of 2 each; splenomegaly, perinodal infiltration, median maximum diameter ≤ 20.5 and median SUVmax ≤ 7.1 of affected LNs in model 2 have score of 1 each) were selected as scheme items for distinguishing KFD from lymphoma. Individuals who have a total score > 8, meet the criteria for KFD. Sensitivity and specificity were high: 86.8% (95% CI: 71.9%, 95.5%) and 96.9% (95% CI: 83.7%, 99.5%), AUC = 0.975 (95% CI: 90.5%, 99.6%), respectively. It can effectively distinguish KFD from lymphoma by clinical and PET/CT parameters.

Kikuchi-Fujimoto disease evolves into lupus encephalopathy characterized by venous sinus thrombosis: a case report

Kikuchi-Fujimoto disease (KFD) is a benign, self-limiting illness that can progress to systemic lupus erythematosus (SLE) in approximately 30% of cases. Neurological injuries can occur in both diseases, albeit with distinct presentations. Venous sinus thrombosis is a serious cerebrovascular complication in patients with neuropsychiatric SLE but is rarely observed in patients with KFD. The involvement of various antibodies, particularly antiphospholipid antibodies, can cause vascular endothelial cell injury, resulting in focal cerebral ischemia and intracranial vascular embolism in SLE. However, there are cases in which thrombotic pathology occurs without antiphospholipid antibody positivity, attributed to vascular lesions. In this report, we present a case of KFD and lupus encephalopathy featuring cerebral venous sinus thrombosis, despite the patient being negative for antiphospholipid antibody. We also conducted a comparative analysis of C3 and C4 levels in cerebrospinal fluid (CSF) and peripheral blood, along with the protein ratio in CSF and serum, to elucidate the pathological changes and characteristics of lupus encephalopathy.

Kikuchi-Fujimoto disease, a rare benign disease with atypical histomorphology: more than meets the eye

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting condition primarily affecting young females. It usually presents with fever and cervical lymphadenopathy of unknown aetiology with a preponderance of the Asian population. Histopathology is critical in making an accurate diagnosis. While the typical microscopic features include paracortical necrosis with debris, histiocytosis with immunoblasts, and absent neutrophils, rarely, KFD can show atypical features like marked immunoblastic proliferation mimicking lymphoma, demonstrate vasculitis mimicking lupus erythematosus, etc. The diagnosis is extremely challenging if such features occur in cases with generalised lymphadenopathy, which is infrequent in KFD. The study aims to describe the morphological, clinical, and immunohistochemical features of KFD and determine the frequency of the atypical features. We also analysed the subtle histological and immunohistochemical features that aid in the diagnosis of atypical cases. Cases reported as KFD over a period of 6 years were retrieved from the archives of histopathology. The morphological features were categorised as typical and atypical. In the atypical cases, the features that aided in the correct diagnosis of KFD were analysed. Out of the 42 cases evaluated, 23.9% (n=10) had generalised lymphadenopathy; 57.2% (n=24) were women with a median age of 25 years. Leukopenia was observed in 42% (n=13) of patients. Typical features were present in 76.2% (n=32) cases and 23.8% (n=10) presented with atypical features. Eight cases were antinuclear antibody-positive. Atypical features included five (50%) cases with vasculitis and panniculitis, and three (30%) cases with large, atypical cells for which immunohistochemistry (IHC) was performed. In two of these cases, the patent sinuses, absence of neutrophils, and IHC with CD68 aided the diagnosis. There is an overlap of clinical and histopathological features between KFD and malignant lymphomas and systemic lupus erythematosus. Given the fact that the atypical features (23.8%) are not rare occurrences in KFD, correlations with clinical findings and ancillary studies are essential to avoid misdiagnosis and inadvertent therapy.

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.

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.

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.

[Recurrent lymphadenitis was Kikuchi-Fujimoto disease]

Kikuchi-Fujimoto disease, or histiocytic necrotizing lymphadenitis, is in most cases a benign disease which affects lymph nodes in the cervical region. Cervical adenopathy and fever are the most common symptoms, and young adults are mostly affected. Lymph node biopsy is the mode of diagnosis with demonstration of paracortical areas of apoptotic necrosis with abundant karyorrhectic debris and a proliferation of histiocytes, plasmacytoid dendritic cells, and CD8+ T cells in the absence of neutrophils. In most cases, the disease is self-limiting but it can be recurrent or evolve to SLE. Treatment varies from symptomatic to more systemic with cortisone and intravenous immunoglobulin.

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.

A rare co-existence of histiocytic necrotizing lymphadenitis with metastatic papillary thyroid carcinoma and review of the literature

Histiocytic necrotizing lymphadenitis (HNL) is a benign, self-limiting disease that is rare clinically. The coexistence of HNL and tumor is rarer. We report a male patient who was preoperatively diagnosed with papillary thyroid carcinoma with cervical lymph nodes metastasis, and the postoperative pathological examination showed histiocytic necrotizing lymphadenitis combined with metastatic papillary thyroid carcinoma in the same single lymph node. More interestingly, Epstein‒Barr virus was positive in these lymph nodes by in situ hybridization. This may suggest a trigger for the coexistence of the two diseases.

Kikuchi-Fujimoto's Disease: A Rare and Underdiagnosed Condition with Possible Renal Involvement

Kikuchi-Fujimoto disease (KFD), or Histiocytic Necrotizing Lymphadenitis, is a rare disease, with worldwide distribution but is best known in Japan and South Asia. The most common feature is cervical lymphadenopathy, accompanied by tenderness or high fever, with night sweats, but it can also be asymptomatic or with a very wide range of symptoms. The diagnosis is histopathological, on excisional biopsy. The Kikuchi-Fujmoto disease can mimic lymphoma but also tuberculosis and some autoimmune diseases, or be associated with them. Nephrologists need to be aware of it, considering the potential renal involvement. The association with systemic lupus erythematosus (SLE) is the most frequent but not the only one. Early diagnosis of this disease can prevent unnecessary investigations and aggressive therapies.

Kikuchi-Fujimoto disease following SARS-CoV-2 vaccination

A previously healthy Japanese woman in her 20s was admitted to our hospital with a 2-week history of fever (39.0°C) and a 1-week history of painful cervical lymphadenopathy. The day before fever onset, she had received her first Pfizer-BioNTech SARS-CoV-2 vaccine in her left arm. She had previously been treated with empirical antibiotics with no improvement. Physical examination revealed painful lymphadenopathy in both posterior cervical regions. CT showed symmetrical lymphadenopathies in the neck, supraclavicular, axillary and inguinal regions as well as hepatosplenomegaly. We suspected lymphoma and performed a lymph node biopsy in the right inguinal region, which revealed necrotising histiocytic lymphadenitis. The patient was, therefore, diagnosed with Kikuchi-Fujimoto disease (KFD). She improved after the corticosteroid therapy. This report highlights the importance of including KFD as a differential diagnosis of lymphadenopathy after SARS-CoV-2 vaccination. Additionally, lymph node biopsy is helpful for diagnosing KFD because it rules out other entities.

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.

Kikuchi-Fujimoto Disease With Unusual Cutaneous Findings

ABSTRACT

We present a case of the rare Kikuchi-Fujimoto disease (KFD) in a 14-year-old patient admitted to UCLA Medical Center with fever, weight loss, and pancytopenia. Physical examination revealed tender subcutaneous nodules and cervical lymphadenopathy. A lymph node biopsy showed findings consistent with KFD. The skin biopsy showed mild superficial dermal edema with neutrophil-predominant inflammation. In addition, rare atypical monocytoid cells were seen. This histologic finding of a Sweet-like morphology has not been reported previously in the literature in association with KFD. The differential diagnosis included Sweet syndrome arising in association with KFD, underlying connective tissue, and an infectious etiology.

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.

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'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.

Kikuchi-Fujimoto disease preceded by lupus erythematosus panniculitis: do these findings together herald the onset of systemic lupus erythematosus?

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare disorder that must be distinguished from systemic lupus erythematosus (SLE). Although a minority of patients with KFD develop SLE, most patients have a self-limited disease. Importantly, KFD can have skin manifestations resembling cutaneous lupus. Therefore, the diagnosis of SLE should be predicated on a complete rheumatologic workup and not on the constellation of skin disease and lymphadenitis. Nonetheless, as our exceedingly rare case illustrates, patients who do not initially meet diagnostic criteria for SLE require dermatologic follow-up. We present a young adult woman who had a remote history of KFD and later presented with combined features of discoid lupus and lupus erythematosus panniculitis (LEP). On subsequent rheumatologic workup, she fulfilled criteria for SLE. We discuss the differential diagnosis of both KFD and LEP and emphasize how strong communication among dermatologists and other healthcare providers is essential in the management of patients with KFD.

Immunopathology of Kikuchi-Fujimoto disease: A reappraisal using novel immunohistochemistry markers

AIMS

Kikuchi-Fujimoto disease (KFD) is a self-limited disease characterised by destruction of the lymph node parenchyma. Few studies have assessed the immunohistological features of KFD, and most employed limited antibody panels that lacked many of the novel immunohistochemistry markers currently available.

METHODS AND RESULTS

We used immunohistochemistry to reappraise the microanatomical distribution of plasmacytoid dendritic cells (pDCs), follicular helper T cells and cytotoxic T cells, B cells, follicular dendritic cell (FDC) meshworks, and histiocytes in lymph nodes involved by KFD. The study group consisted of 138 KFD patients (89 women; 64.5%) with a median age of 27 years (range, 3-50 years). Cervical lymph nodes were most commonly involved, in 108 (78.3%) patients. The numbers of pDCs were increased, predominantly around and within apoptotic areas and the paracortex, and tapering off within xanthomatous areas. pDCs formed sizeable tight clusters, most notably around apoptotic/necrotic areas. T cells consisted mostly of CD8-positive cells with predominant expression of T-cell receptor-β. There were notable increases in the numbers of CD8-positive T cells within lymphoid follicles, and their numbers correlated with alterations in FDC meshworks (P < 0.001). The number of follicular helper T cells was decreased within distorted FDC meshworks. CD21 highlighted frequent distortion of FDC meshworks, even in lymph node tissue that was distant from apoptotic/necrotic areas. Distorted FDC meshworks spanned all morphological patterns, and FDC meshwork characteristics (intact; distorted; remnant/nearly absent) correlated with morphological patterns (P < 0.01).

CONCLUSIONS

The immunohistological landscape of KFD is complex and characterised by increased numbers of pDCs that frequently cluster around apoptotic/necrotic foci, increased numbers of cytotoxic T cells, and substantial distortion of FDC meshworks.

Kikuchi-Fujimoto Disease-Like Inflammatory Reaction in a Silicone Breast Implant Seroma

INTRODUCTION

Kikuchi-Fujimoto disease (KFD) may have an autoimmune etiology and some cases have been associated with silicone breast implants. Cytomorphologic features of the disease have been well characterized by fine-needle aspiration of lymph nodes. They are so specific as to permit a precise cytologic diagnosis. Cytologic features have not been reported in fluid specimens.

CASE

A 33-year-old female presented with a unilateral periprosthetic silicone breast seroma. The fluid was drained, and cytological analysis revealed numerous lymphocytes with no neutrophils, karyorrhectic nuclear debris, and peculiar histiocytes with eccentrically located nuclei showing a crescentic shape. Many of those histiocytes showed intracellular apoptotic debris.

CONCLUSION

A Kikuchi disease-like inflammatory reaction is possible not only in axillary and cervical lymph nodes of patients with silicone breast implants but also in breast seromas. There is still not enough evidence to establish if there is an association between KFD and breast implants. A detailed cytologic examination of periprosthetic silicone breast seromas may help answer this question. In any case, pathologists must be aware of this possibility. Cytologic features are characteristic enough to permit differentiation from breast implant-associated anaplastic large-cell lymphoma.

Report of a rare case of histiocytic necrotizing lymphadenitis with bilateral pleural effusion diagnosed via cervical lymph node biopsy

CONTEXT

Histiocytic necrotizing lymphadenitis (HNL) is a rare disorder that is often benign and self-limiting. There have been reports of co-occurrence of HNL with other diseases, including systemic lupus erythematosus, hemophagocytic syndrome and antiphospholipid syndrome.

CASE REPORT

Here, we report a case in which a patient experienced unexplained fever, swelling of the cervical lymph node and bilateral pleural effusion and was ultimately diagnosed with HNL based on results from a lymph node biopsy. After treatment with glucocorticoid, the patient regained normal body temperature, the swelling of the lymph nodes disappeared and the pleural effusion was reabsorbed.

CONCLUSIONS

The pathogenesis of HNL remains unclear, and pleural effusion is rarely reported in HNL patients. We presented this case to improve diagnostic awareness of this condition among clinicians and help reduce the likelihood of misdiagnosis.

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.

CT pattern analysis of necrotizing and nonnecrotizing lymph nodes in Kikuchi disease

Objective

The purpose of this study was to determine whether a CT interpretation with imaging pattern analysis differentiates Kikuchi disease (KD) from the two more frequently encountered differential lymph nodes diagnoses of tuberculous lymphadenopathy (TL) and reactive hyperplasia (RH).

Materials and methods

Between January 2012 and July 2015, 20 patients with KD (6 men, 14 women; mean age, 27.80 years), 36 patients with RH (10 men, 26 women; mean age, 33.08 years) and 34 patients with TL (17 men, 17 women; mean age, 39.82 years) were pathologically diagnosed using US-guided fine needle aspiration biopsy, core needle biopsy, or surgical excisional biopsy. We recorded the total number, location, and size of the affected cervical lymph nodes, and two radiologists reviewed the characteristic imaging findings, including the presence of necrosis, cortical enhancement pattern, perinodal infiltration, conglomeration and nodal calcification, to form a consensus. In addition, we compared two attenuation indices on the nonnecrotic portion of the affected lymph nodes, nodal cortical attenuation (NCA) and the ratio of NCA to the adjacent muscle (NCA/M).

Results

Conglomeration, enhancement pattern and NCA/M values were independent predictive CT features to distinguish KD from RH. Age and enhancement pattern discriminated KD from TL. Only the mean NCA/M value was a statistically significant CT feature (p = .008) in differentiating KD from both RH+TL. The mean NCA/M of KD (1.67 ± 0.20) was significantly higher than that of RH (1.49 ± 0.20) or TL (1.47 ± 0.21).

Conclusion

Our results indicate that in case of nonnecrotic lymphadenopathy, a higher NCA/M index can differentiate KD from RH and TL. In addition, the enhancement pattern according to the degree of necrosis discriminated between KD and TL in the case of necrotic lymphadenopathy.