Histiocytic necrotising lymphadenitis (Kikuchi-Fujimoto disease) in Saudi Arabia: clinicopathology and immunohistochemistry

Kikuchi Disease "A Lupus Mimicker": A Case Report

Kikuchi disease, also called, Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis, is a rare self-limiting illness with an unknown etiology and pathogenesis. It is predominantly seen among young females. The cardinal clinical features include fever and cervical lymphadenopathy. Skin eruptions have also been reported. In Oman, two cases have been reported to date, in 2005 and 2020, with only one case exhibiting skin manifestations. There is a paucity of disease in our country and worldwide. In this case report, we discuss the diagnosis of Kikuchi disease in a previously healthy 17-year-old Omani female who presented with fever, cervical lymphadenopathy, and malar rash. The clinical picture in this case resembled that of systemic lupus erythematosus. Due to the rarity of Kikuchi disease, particularly in our region, it is crucial to consider it as a differential diagnosis when a patient exhibits the aforementioned symptoms to prevent misdiagnosis and inappropriate treatment, as it can easily be misdiagnosed as systemic lupus erythematosus.

Pathological Features and Clinical Characteristics of Kikuchi-Fujimoto Disease: A Tertiary Hospital Experience in Riyadh, Saudi Arabia

Background Kikuchi-Fujimoto disease (KFD) - also known as necrotizing histiocytic lymphadenitis - is a benign histiocytic lymphadenitis known for its low incidence and misdiagnosis that occurs mostly in young Asian females more than males. This disease resolves spontaneously in a few months with a low risk of relapse (one in 30 patients) after resolution. Objectives The aim of this study is to share King Abdulaziz Medical City's (KAMC's) experience with KFD by determining its clinicopathological characteristics. Materials and methods In this study, we reviewed histopathological slides and pathological reports of all lymphadenopathy cases (683 cases) in the period between January 2008 and December 2018. Results Forty-four cases of KFD were found and their clinicopathological characteristics were recorded. There is a slight female predominance (59% females versus 41% males) with a wide age range from 10 months to 97 years (mean = 28.8). The majority of the cases (63.6%) are seen in young adults (between 21 and 40 years). Association with autoimmune diseases was shown by 20.5% of cases while viral infection association was shown by few cases. Most cases showed remission (59%) and no deaths were reported upon follow-up. Histopathologically, the majority of cases have proliferative type followed by the necrotic type and few cases showed xanthomatous type. Conclusions Our study has the largest number of KFD cases in this region. It is obvious that KFD has clinical, radiological, and pathological features that overlap with malignancy, especially lymphoma. Knowing this disease and careful diagnostic approach can help avoid misdiagnosis.

Kikuchi-Fujimoto disease can present as delayed lymphadenopathy after COVID-19 vaccination

Following COVID-19 vaccination, ipsilateral axillary and cervical lymphadenopathy may occur, called vaccine-related hypermetabolic lymphadenopathy, which is considered reactive lymphadenopathy. We report here a case of Kikuchi-Fujimoto disease, which occurred three months after vaccination with COVID-19 vaccine. The patient had cervical and axillary lymph node enlargement and a short-term fever that resolved spontaneously after the first and second vaccines. On the 90th day after the first vaccination, the patient developed a high fever and pathologically diagnosed necrotizing lymphadenitis in the axilla, which was diagnosed as Kikuchi-Fujimoto disease. Gallium scintigraphy showed localized swelling and strong uptake in the ipsilateral axilla. It implies the possibility of Kikuchi-Fujimoto Disease in axillary drainage lymph nodes in association with COVID-19 vaccine. Although only a few cases have been reported so far, this case is novel because of its later onset and diagnosis based on pathological and gallium scintigraphy imaging findings.

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.

Pattern of lymph node pathology in western Saudi Arabia

BACKGROUND

This study aimed to characterize the histopathological pattern of lymph node pathology among Saudi patients and to highlight the age and gender variations of these lesions as base line data.

MATERIALS AND METHODS

We retrospectively analyzed the data from lymph node biopsy specimens received at the Department of Pathology, King Fahad Hospital, Madinah, Saudi Arabia from January 2006 to December 2013.

RESULTS

Of the 289 lymph node biopsy specimens received, 154 (53.3%) were from males and 135 (46.7%) from females giving a male: female ratio of 1.14:1. Age of the patients ranged from 2.5 to 96 years with a mean age 33.9 years. The commonest lymph node group affected was the cervical (30.4%) followed by axillary (9.7%) and inguinal (8.7%). Malignant lymphoma [71 Hodgkin's disease (HD), 57 non Hodgkin's lymphoma (NHL)] 128 (44.3%), reactive hyperplasia 68 (23.5%), and tuberculosis 41 (14.2%) were the common causes of lymph node enlargement. While HD, reactive hyperplasia and tuberculosis were commonest in young adult patients (10-29 years old) and rare above the age of 50 years; NHL was the predominant cause of lymph node enlargement above 50 years.

CONCLUSIONS

Lymph node biopsy plays an important role in establishing the cause of lymphadenopathy. Among the biopsied nodes, lymphomas were the most common (44.3%) followed by non-specific reactive hyperplasia (23.5%) and tuberculous lymphadenitis (14.2%).

Lymphadénite histiocytaire nécrosante ou maladie de Kikuchi-Fujimoto

Kikuchi-Fujimoto disease (KFD), first described independently by Kikuchi and Fujimoto in 1972, is a subacute necrotizing lymphadenitis of unknown cause. Although most frequent in young Asian women, KFD has a worldwide distribution. Clinically, KFD is characterized by lymphadenitis of one or more lymph nodes, predominantly in the posterior cervical region, fever, and leukopenia in up to 50% of cases. Extranodal manifestations can occur, especially skin lesions and aseptic meningitides. Diagnosis is usually confirmed by analysis of samples from an excisional biopsy of the affected nodes. Histologically, the lesions affect the cortical and paracortical areas of the node. Characteristic features include focal necrosis predominantly in the paracortical region with abundant karyorrhectic debris and atypical mononuclear cells around the necrotic zone (crescent-shaped histiocytes, plasmacytoid monocytes, and small lymphocytes and immunoblasts, mostly CD3(+)/CD8(+)), most often with an intact lymph node capsule, an absence of neutrophils, and a paucity of plasma cells. KFD has been classified into three histological subtypes and is thought to progress from the proliferative type (> 50%) to the necrotizing type (30%) and finally resolve into the xanthomatous type (< 20%). Differential diagnoses should include malignant lymphoma, infectious diseases such as toxoplasmatic lymphadenitis, tuberculous lymphadenitis and cat scratch disease, and systemic lupus erythematosus (SLE). The cause of KFD is unknown: a viral infection has been suggested, but not demonstrated, possibly involving human herpes virus 8 or Epstein-Barr virus. Apoptotic cell death plays a role: proliferating CD8(+) T-lymphocytes act as both killers and victims in the apoptotic process via Fas and perforin pathways. The course is usually benign with resolution in a few months with the use of antiinflammatory drugs. Regular follow-up is required because SLE may develop several years after the onset of Kikuchi-Fujimoto disease.

Histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto's disease) mimicking systemic lupus erythematosus: a review of two cases

Kikuchi-Fujimoto's disease (KFD), or histiocytic necrotizing lymphadenitis, is a benign and self-limited lymphadenitis commonly found in young women. It often shares clinical features with systemic lupus erythematosus (SLE), such as arthralgias, fever and leukopenia. The etiology of KFD remains unknown and controversial. Clinical course is favorable, with spontaneous remission in less than four months in almost all cases. Herein, we present two cases. The former is a 53-year old woman presenting with cervical lymphadenopathy, arthralgia, pancytopenia and positive antinuclear antibody (ANA). Lymph node biopsy revealed histopathological features compatible with Kikuchi-Fujimoto histiocytic necrotizing lymphadenitis. The latter patient was a 20-year old woman presenting with left cervical lympadenopathy, a butterfly rash that was reminiscent of SLE, and a positive antinuclear antibody. Based upon clinical, histological and laboratory findings, the diagnosis of SLE was excluded. Careful attention should be paid to differentiating between KFD and SLE, because of their similar presentations, yet different clinical courses and therapeutic requirements.